HK1088850B

HK1088850B - Compositions for affecting weight loss

Info

Publication number: HK1088850B
Application number: HK06110959.2A
Authority: HK
Inventors: E‧韦伯; M‧A‧考利
Original assignee: Nalpropion Pharmaceuticals, Inc.
Priority date: 2003-04-29
Filing date: 2004-04-21
Publication date: 2010-12-17

Description

Composition for affecting weight loss

Background

Technical Field

The present invention relates to pharmaceutical compositions and methods for treating obesity and affecting weight loss in an individual.

Description of the Related Art

Obesity is a disease characterized by the accumulation of excess fat in the body. Obesity has been recognized as one of the major causes of disease and is emerging as a global problem. In the general population, examples of increased obesity are associated with examples of increased complications such as hypertension, non-insulin dependent diabetes mellitus, arteriosclerosis, dyslipidemia, certain forms of cancer, sleep apnea, and osteoarthritis.

Obesity is defined in terms of Body Mass Index (BMI). BMI was calculated as weight (kg)/[ height (m) ] 2. BMI is classified into one of these categories for adults over 20 years, as directed by The United states centers for disease control and prevention (CDC) and The World Health Organization (WHO) (physical status: The use and intervention degree anthrof anthropometry. geneva, Switzerland: World Health Organization 1995.WHOTechnical Report Series): less than 18.5 is considered to be underweight, 18.5-24.9 is considered to be normal, 25.0-29.9 is considered to be overweight, and 30.0 and above is considered to be obesity.

Obesity was generally considered a psychological problem before 1994. The 1994 discovery of adipostatic hormone leptin (Zhang et al, "Positional cloning of the mouse organism genes and human homologue," Nature 1994; 372: 425-432) raised the recognition that obesity may have a biochemical basis in some cases. A corollary to this recognition is that the treatment of obesity can be achieved by chemical means. Since then, many of these chemotherapies have entered the market. The best known of these attempts is the introduction of Fen-Phen, a combination of fenfluramine and phentermine. Unfortunately, fenfluramine was found to cause heart valve complications, which in some cases led to death of the user. Since then, fenfluramine exited the market. Some limited success has been achieved with other combination therapies, particularly in psychogenic eating disorders. One such example is Devlin, et al, int.J. Eaiting disease.28: 325-332, 2000, in which phentermine and fluoxetine in combination show some effects in the treatment of patients suffering from eating disorders (binding eating disorders). Of course, this disease is a problem for only a small percentage of people.

Apart from those individuals who meet the strict definition of medical obesity, a significant portion of the adult population is overweight. These overweight individuals will also benefit from the effectiveness of effective weight loss compositions. Accordingly, there is an unmet need in the art to provide pharmaceutical compositions that can affect weight loss without causing other side effects.

Brief description of the invention

Disclosed are compositions for affecting weight loss comprising a first compound and a second compound, wherein the first compound is an opioid antagonist and the second compound results in increased agonism of a melanocortin 3 receptor (MC3-R) or a melanocortin 4 receptor (MC4-R) as compared to normal physiological conditions.

Also disclosed are methods of affecting weight loss, increasing energy expenditure, increasing satiety in an individual, or suppressing appetite in an individual, comprising identifying an individual in need thereof and treating the individual to antagonize opioid receptor activity and to increase alpha-MSH activity.

Detailed description of the preferred embodiments

Arcuate nuclear neurons are known to respond to a wide array of hormones and nutrients, including leptin, insulin, sex steroids, and glucose. In addition to possible transport mechanisms, peripheral material can cause these neurons to enter and project through the arcuate cell body into the median eminence, which is considered to be the area of the periventricular organ that lacks the blood-brain barrier. Cone et al, "The arc elementary as a reduce for reverse signals to energy homeostatis," Int' lJournal of Obesity (2001)25, Suppl5, S63-S67.

Administration of exogenous leptin activates many different neurons in hypothalamic and brain stem cell populations with leptin receptors. Leptin-responsive neurons in the arcuate nucleus include those comprising neuropeptide y (npy) and agouti-related peptide (AgRP) in the middle part of the nucleus and those comprising pre-opio melanocortin (POMC) and its derivatives, including alpha-melanocyte stimulating hormone (alpha-MSH), and cocaine and amphetamine-related transcripts (CART). Saper et al, "The need to feed: homestatic and sonic control of proofing, "Neuron, 36: 199-211(2002).

Leptin-reactive POMC neurons in the arcuate nucleus are thought to cause anorexia and weight loss through the action of alpha-MSH at melanocortin 3 and/or 4 receptors (MC3-R, MC 4-R). MC3-R is expressed at the highest level in the hypothalamus and limbic system, while MC4-R mRNA is expressed in virtually all major brain regions. Some of the metabolic effects caused by stimulation of MC4-R are decreased food absorption and increased energy expenditure through stimulation of thyrotropin-releasing hormone and activation of the sympathetic nervous system. Targeted deletion of the MC4-R gene product results in obesity, hyperphagia, hyperinsulinemia, and reduced energy expenditure. Targeted deletion of MC3-R increases obesity due to reduced energy expenditure. Korner et al, "The engineering science of body weight adjustment and positioning on object flow," J.Clin.invest.111 (5): 565-570(2003). Thus, increased concentrations of alpha-MSH in the Central Nervous System (CNS) increase its effects on MC3-R and/or MC4-R and lead to a decrease in appetite.

At the same time as the release of alpha-MSH, the POMC neurons also release beta-endorphin. Beta-endorphin is an endogenous agonist of the mu-opioid receptor (MOP-R) found on POMC neurons. Stimulation of MOP-R reduces alpha-MSH release. This is a biofeedback mechanism that controls the concentration of alpha-MSH in the CNS under normal physiological conditions. Thus, blockade of MOP-R by opioid antagonists would block the feedback mechanism, which results in sustained secretion of α -MSH and an increase in its concentration in the CNS.

The second group of neurons in the arcuate nucleus strongly inhibits POMC neurons. These POMC-inhibiting neurons secrete NPY, the neurotransmitter gamma-aminobutyric acid (GABA) and AgRP. NPY and GABA inhibit POMC neurons via NPY Y1 receptors and GABA receptors, respectively. Thus, NPY and GABA inhibit α -MSH release in the arcuate nucleus and are therefore feeding stimulants. Leptin is known to inhibit the release of GABA from the NPY terminals that form synapses on POMC neurons, while ghrelin, orexin (orexigenic peptide), stimulates ghrelin receptors on NPY neurons and increases the secretion of NPY and GABA on POMC cells, which in turn inhibits the release of α -MSH.

AgRP stimulates food absorption in rats by antagonism of the interaction of alpha-MSH at MC 4-R. The expression of the AgRP gene is inhibited by leptin.

5-hydroxytryptamine, also known as 5-hydroxytryptamine or 5-HT, activates POMC neurons to secrete α -MSH. However, 5-hydroxytryptamine is absorbed and eliminated by the action of specific transporters, thus rendering a single 5-hydroxytryptamine molecule with a short-acting effect. Selective 5-hydroxytryptamine reuptake inhibitors (SSRIs) are known to prevent the uptake of 5-hydroxytryptamine and to increase its concentration in the CNS. SSRIs therefore also increase the secretion of alpha-MSH and its concentration in the CNS.

Dopamine also increases the α -MSH secretion activity of POMC neurons. Like 5-hydroxytryptamine, dopamine is also absorbed and eliminated by action, giving a single dopamine molecule a short-term effect. Dopamine reuptake inhibitors, which prevent or reduce dopamine uptake, can also increase alpha-MSH secretion and its concentration in the CNS.

Thus, increasing alpha-MSH secretion by various mechanisms, such as reuptake inhibition of 5-hydroxytryptamine, is one of the strategies for the methods and pharmaceutical compositions of the present invention used to produce the effects of biochemical anorexia.

The present invention provides a multifaceted combination therapy for the problem of weight loss. It is not directed against a single molecule, messenger or receptor, but rather acts at multiple points in the feeding and satiety pathway. Aspects of the invention relate to increasing the concentration of alpha-MSH in the CNS by stimulating its release, inhibiting its metabolism, reducing its antagonism of the interaction at MC3/4-R and inhibiting any feedback mechanism that slows or prevents its release. Aspects of the invention include pharmaceutical compositions having components that perform one or more of these functions. The present inventors have found that the combination of two or more compounds disclosed herein results in a synergistic effect that affects weight loss more rapidly and on a more durable basis.

Thus, in a first aspect, the present invention relates to a composition comprising a first compound and a second compound for use in the treatment of obesity or affecting weight loss, wherein the first compound is an opioid antagonist and the second compound causes an increase in agonism of a melanocortin 3 receptor (MC3-R) or a melanocortin 4 receptor (MC4-R) as compared to normal physiological conditions.

In certain embodiments, the second compound results in an increase in POMC neuronal activity that results in greater agonism at MC3-R and/or MC 4-R.

In certain embodiments, the opioid antagonist antagonizes the μ -opioid receptor (MOP-R) in the mammal. The mammal may be selected from the group consisting of mouse, rat, rabbit, guinea pig, dog, cat, sheep, goat, cow, primate such as monkey, chimpanzee and ape, and human.

In some embodiments, the opioid antagonist is selected from the group consisting of alvimopan, norbinaltorphimine, nalmefene, naloxone, naltrexone, methylnaltrexone, and nalorphine, and pharmaceutically acceptable salts or prodrugs thereof.

In other embodiments, the opioid antagonist is a partial opioid agonist. Such compounds have some agonist activity at opioid receptors. However, because they are weak agonists, they actually act as antagonists. Examples of partial opioid agonists include pentacozine, buprenorphine, nalorphine, propiram, and lofexidine.

The term "pharmaceutically acceptable salt" refers to a formulation of a compound that does not cause significant irritation to the organism to which it is administered and does not abrogate the biological activity and properties of the compound. Pharmaceutically acceptable salts can be obtained by reacting a compound of the present invention with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, salicylic acid, and the like. Pharmaceutically acceptable salts can also be obtained by reacting a compound of the invention with a base to form a salt such as an ammonium salt, an alkali metal salt such as a sodium or potassium salt, an alkaline earth metal salt such as a calcium or magnesium salt, an organic base salt such as dicyclohexylamine, N-methyl-D-glucamine, tris (hydroxymethyl) methylamine, and salts thereof with amino acids such as arginine, lysine, and the like.

"prodrug" refers to an agent that is converted in vivo to the parent drug. In some cases, prodrugs are often useful because they are easier to administer than the parent drug. For example, by oral administration, they may be bioavailable but not the parent drug. The prodrugs also have improved solubility in pharmaceutical compositions or exhibit increased palatability or are easy to formulate relative to the parent drug. An example, without limitation, of a prodrug is a compound of the invention that is administered as an ester ("prodrug") to facilitate its passage across a cell membrane where water solubility is detrimental to flow, but which is then metabolically hydrolyzed to the carboxylic acid, the active entity, once inside the cell where water solubility is beneficial. Another example of a prodrug may be a short peptide (polyamino acid) bound to an acid group, where the peptide is metabolized to provide the active moiety.

In certain embodiments, the second compound in the pharmaceutical composition of the invention triggers the release of alpha-melanocyte stimulating hormone (alpha-MSH). The second compound may increase extracellular 5-hydroxytryptamine concentration in the hypothalamus. In some embodiments, the second compound is selected from the group consisting of a selective 5-hydroxytryptamine reuptake inhibitor (SSRI), a 5-hydroxytryptamine 2C agonist, and a 5-hydroxytryptamine 1B agonist. In another embodiment, the second compound is selected from, for example, the group consisting of fluoxetine, fluvoxamine, sertraline, paroxetine, citalopram, escitalopram, sibutramine, duloxetine, and venlafaxine, and pharmaceutically acceptable salts or prodrugs thereof.

The terms "5-hydroxytryptamine 1B receptor", "5-hydroxytryptamine 2C receptor", "5 HT1B receptor", and "5 HT2C receptor" refer to receptors more commonly found in rodents. It is understood by those skilled in the art that other mammals have 5-hydroxytryptamine receptors similar in function and form to these receptors on a variety of neurons. Agonists or antagonists, 5-hydroxytryptamine receptors, on these non-rodent, preferably human, species are within the scope of the invention.

In certain embodiments, the second compound inhibits expression of an AgRP gene or production or release of wild grey protein-related protein (AgRP). In some of these embodiments, the second compound inhibits the activity of an AgRP-expressing neuron.

In other embodiments, the second compound inhibits the expression of the NPY gene or the production or release of neuropeptide y (NPY). In some of these embodiments, the second compound inhibits the activity of a neuron expressing NPY. In further embodiments, the second compound is selected from the group consisting of an NPY antagonist, a ghrelin antagonist, and a leptin. In certain other embodiments, the second compound antagonizes (agonize) NPY Y2 receptor.

Other embodiments of the invention include those wherein the second compound is selected from the group consisting of gamma aminobutyric acid (GABA) inhibitors, GABA receptor antagonists and GABA channel antagonists. By "GABA inhibitor" is meant a compound that reduces the production of GABA in cells, reduces the release of GABA from cells or reduces the activity of GABA at its receptor by preventing the binding of GABA to GABA receptors or by minimizing the effect of such binding. The GABA inhibitor may be a 5-HT1b agonist or another agent that inhibits NPY/AgRP/GABA neuronal activity. In addition, GABA inhibitors may inhibit the expression of the AgRP gene or GABA inhibitors may inhibit the production or release of AgRP. However, it is understood that 5-HT1b agonists may inhibit NPY/AgRP/GABA neurons (and thus activate POMC neurons) without acting as inhibitors of the GABA pathway.

In certain other embodiments, the GABA inhibitor increases the expression of the POMC gene. In some of these embodiments, the GABA inhibitor increases the production or release of a pro-opiomelanocortin (pomc) protein. In certain other embodiments, the GABA inhibitor increases activity on POMC expressing neurons. In some embodiments, the GABA inhibitor is topiramate.

In other embodiments, the second compound is a dopamine reuptake inhibitor. Phentermine is an example of a dopamine reuptake inhibitor. In certain other embodiments, the second compound is a norepinephrine reuptake inhibitor. Examples of norepinephrine reuptake inhibitors include bupropion, thionisoxetine, and reboxetine. Other embodiments include those wherein the second compound is a dopamine agonist. Some commercially available dopamine agonists include cabergoline, amantadine, lisuride, pergolide, ropinirole, pramipexole and bromocriptine. In additional embodiments, the second compound is a norepinephrine releasing agent, such as bupropion or a mixed dopamine/norepinephrine reuptake inhibitor, such as atomoxatine.

In certain other embodiments, the second compound is a 5-HT1b agonist, such as sumatriptan, almotriptan, naratriptan, frovatriptan, rizatriptan, zomitriptan and elitriptan.

In additional embodiments, the second compound is an anticonvulsant. The anticonvulsant may be selected from the group consisting of zonisamide, topiramate, pentobarbital, lorazepam, flunitrazepam, chlorambucil, tiagabine, gabapentin, phenytoin, carbamazepine, valproate, felbamate, levetiracetam, oxcarbazepine, lamotrigine, ethosuximide and ethosuximide.

In certain embodiments, the second compound may itself be a combination of two or more compounds. For example, the second compound may be a combination of a dopamine reuptake inhibitor and a norepinephrine reuptake inhibitor, such as bupropion and mazindol. Alternatively, the second compound may be a combination of an SSRI and a norepinephrine reuptake inhibitor, such as sibutramine, venlafaxine, and duloxetine.

In certain embodiments, the second compound is an activator of POMC neurons. Examples of POMC activators include Ptx1 and interleukin 1 beta, (IL-1 beta).

In another aspect, the invention relates to a method of affecting weight loss comprising identifying an individual in need thereof and treating the individual to antagonize opioid receptor activity and increase alpha-MSH activity.

In certain embodiments, the subject has a Body Mass Index (BMI) greater than 25. In other embodiments, the subject has a BMI greater than 30. In other embodiments, the subject has a BMI greater than 40. However, in some embodiments, the individual may have a BMI of less than 25. In these embodiments, weight loss may be affected for health or cosmetic benefit purposes, thereby reducing BMI even further.

In some embodiments, opioid receptor activity is antagonized by administering an opioid receptor antagonist. The opioid receptor antagonist may be a MOP receptor antagonist. In some embodiments, the opioid receptor antagonist is selected from alvimopan, norbinaltorphimine, nalmefene, naloxone, naltrexone, methylnaltrexone, and nalorphine, and pharmaceutically acceptable salts or prodrugs thereof.

In some embodiments as described above, the activity of α -MSH is increased by administering a compound, wherein the compound triggers the release of α -MSH or increases the activity of neurons expressing α -MSH. In some embodiments, the compound is a selective 5-hydroxytryptamine reuptake inhibitor (SSRI) or a specific 5-HT receptor agonist. Examples of SSRIs that can be used in the present invention include fluoxetine, fluvoxamine, sertraline, paroxetine, citalopram, escitalopram, sibutramine, duloxetine, and venlafaxine, and pharmaceutically acceptable salts or prodrugs thereof.

In other embodiments, the compound is a gamma-aminobutyric acid (GABA) inhibitor. The GABA inhibitor may be a 5-HT1b receptor agonist. GABA inhibitors may inhibit the expression of the AgRP gene or they may inhibit the production or release of AgRP. GABA inhibitors may inhibit the expression or release of NPY. In certain embodiments, the GABA inhibitor inhibits the activity of neurons expressing AgRP. For example, the GABA inhibitor may be topiramate, 1- (2- (((diphenylmethylene) amino) oxy) ethyl) -1, 2, 5, 6-tetrahydro-3-pyridinecarboxylic acid hydrochloride (NNC-711) or vigabatrin.

In certain embodiments, the methods of the invention described above are practiced under conditions in which the subject does not suffer from Prader-Willi syndrome or suffers from eating disorders. Thus, some embodiments of the invention are distinguished from combination therapies comprising SSRI anti-inhibitors (e.g., fluoxetine) for the treatment of physiological eating disorders, such as the development of eating disorders or Prader-Willi syndrome. In these embodiments, the target population is a population of individuals in need or requirement of weight loss other than a population in need of treatment for Prader-Willi syndrome or suffering from eating disorders.

Individuals with depression may gain weight due to their depression. In addition, some depressed individuals gain weight due to side effects of treating depression. In certain embodiments, the methods of the invention described above are practiced under conditions in which the individual does not suffer from depression. In some embodiments, the overweight condition of the individual is not due to treatment for depression.

In other embodiments, the methods of the invention described above are practiced under conditions such that if naltrexone is used to antagonize the opioid receptor, the release of α -MSH is not stimulated by fluoxetine. However, the combination of naltrexone and fluoxetine can be used to reduce the weight of individuals who wish to lose weight, whether or not they are clinically classified as obese. These individuals may include those with a BMI in excess of 25, or those with a BMI of less than 25 who still desire to lose excess weight. This particular combination may also be used to treat general obesity. In certain embodiments, the subject in whom excess weight loss is desired does not suffer from a eating disorder.

In some embodiments, the treating step of the above methods comprises administering to the individual a first compound and a second compound, wherein the first compound is an opioid antagonist and the second compound increases the activity of a-MSH.

In some embodiments, the first compound and the second compound are administered more or less simultaneously. In other embodiments, the first compound is administered before the second compound. In another embodiment, the first compound is administered after the second compound.

In certain embodiments, the first compound and the second compound are administered separately. In other embodiments, the first compound and the second compound are covalently linked to each other to form a single chemical entity. The single chemical entity is then digested and metabolized into two separate physiologically active chemical entities, one of which is a first compound and the other of which is a second compound.

In some embodiments, the compositions of the present invention are a combination of:

SSRIs in combination with dopamine reuptake inhibitors, dopamine/norepinephrine reuptake inhibitors, opioid antagonists, partial opioid agonists, GABA inhibitors, peripherally acting weight loss agents such as metformin or peptides such as PYY, PYY_3-36Or leptin;

5-hydroxytryptamine in combination with a dopamine reuptake inhibitor, a dopamine/norepinephrine reuptake inhibitor, an opioid antagonist, a partial opioid agonist or a GABA inhibitor;

dopamine reuptake inhibitors in combination with norepinephrine reuptake inhibitors, norepinephrine releasers, norepinephrine agonists, opioid antagonists, partial opioid agonists, GABA inhibitors, adenosine compounds, cholinergic receptor antagonists or peptides, such as PYY, PYY_3-36Or a leptin;

dopamine/norepinephrine reuptake inhibitors in combination with opioid antagonists, partial opioid agonists, GABA inhibitors or peripherally acting weight loss agents such as metformin;

dopamine agonists combined with opioid antagonists, partial opioid agonists, GABA inhibitors or peptides such as PYY, PYY_3-36Or leptin.

Examples of norepinephrine agonists include phendimetrazine and benzphetamine. Examples of adenosine compounds include all xanthine derivatives such as adenosine, caffeine, theophylline, theobromine and aminophylline. An example of a cholinergic receptor antagonist is nicotine.

In another aspect, the invention relates to a method of increasing satiety in an individual, comprising identifying an individual in need thereof and treating said individual to antagonize opioid receptor activity and increase alpha-MSH activity.

In some embodiments, the first compound and the second compound are administered at about the same time. In other embodiments, the first compound is administered before the second compound. In other embodiments, the first compound is administered after the second compound.

In another aspect, the invention relates to a method of suppressing appetite in an individual, the method comprising identifying an individual in need thereof and treating the individual to antagonize opioid receptor activity and increase alpha-MSH activity.

In another aspect, the invention relates to a method of increasing energy expenditure in an individual, comprising identifying an individual in need thereof and treating the individual to antagonize opioid receptor activity and increase alpha-MSH activity.

In certain embodiments disclosed herein, a pharmaceutical composition comprising two or more compounds is administered to an individual to affect weight loss. In some of these embodiments, each compound is a separate chemical entity. However, in other embodiments, the two compounds are linked together by a chemical bond, such as a covalent bond, such that the two different compounds form separate parts of the same molecule. The chemical bonds are selected such that upon entry into the body, the bonds are cleaved, such as by enzymatic action, acid hydrolysis, base hydrolysis, or the like, and two separate compounds are then formed.

Thus, in another aspect, the invention relates to a synthetic pathway for a novel molecule wherein an opioid antagonist is linked to a selective 5-hydroxytryptamine reabsorption inhibitor (SSRI) by a flexible linker.

Data previously obtained from studies on the structure-activity relationship (SAR) in the mu-opioid antagonist family can be used as a guide to determine which antagonist to use and one or more optimal locations on the antagonist molecule to attach a tether (tether) to maintain the high potential and selectivity of the antagonist. Similarly, SAR data in the SSRIs family can be used as a guide to determine which inhibitor to use and one or more optimal locations on the inhibitor molecule to attach a tether (tether) to maintain high potency and selectivity of the inhibitor. The tether or linker moiety is selected from those that have proven useful for linking bioactive molecules together. Disclosed herein are representative opioid antagonists, linkers, and SSRI molecules that can be attached together in various combinations to form heterobivalent therapeutic molecules.

The structure-activity relationships of opioid agonists and antagonists have been reviewed. See, e.g., Zimmerman, D.M; leaner, j.d.j.med.chem.1990, 33, 895; portoghese, p.s.j.med.chem.1992, 35, 1927; carroll, f.i.j.med.chem.2003, 46, 1. The opioid antagonists, nalmefene (1), naltrexone (2), naloxone (3) and naltrexamine (4), are thebaine derived structures that share a common opiate type template. Mu-subtype selective opioid antagonists are quite popular agents of interest for the treatment of obesity (Glass, M.J.; Billington, C.J.; Levine, A.S. neuropeptides 1999, 33, 350) and CNS disorders (Reneric, J.P; Bouvard, M.P. CNS Drugs 1998, 10, 365).

1. Nalmefene 2. naltrexone 3 naloxone 4 beta-naltrexamine

N-methyl and N-2-phenylethyl substituted opioids tend to exhibit opioid agonist activity while N-allyl and N-cyclopropylmethyl substituted analogs tend to exhibit opioid antagonist activity. Any N-attached linker moiety is greater than methyl. If the linker moiety does not mimic the 2-phenylethyl group, this linked opioid would be expected to act as an opioid antagonist. Thus, the nitrogen atoms of nalmefene and naltrexone (and naloxone) are suitable sites for attachment of linker moieties. With respect to substitutions at other sites on these opioids, less SAR information is available, however, linking the linker unit to one or the other of the carbon atoms with one or more hydrogen atoms is still an option.

Both nalmefene and naltrexone are potent mu-opioid antagonists. The only structural difference is that nalmefene has one methylene group instead of the ketone oxygen atom on naltrexone. Thus, it is desirable that significant structural changes at the ketonic oxygen site of naltrexone do not significantly affect the efficacy of the antagonist. Thus, the linker can be attached to the methylene group on nalmefene without a significant reduction in the efficacy of the antagonist. Carbonyl derivatives of naloxone are well known and include symmetrical azines (═ N-N ═), mixed azines (Schmidhammer, h.; Kaspar, f.; Marki, a.; bordecodi, a.helv. chim.acta 1994, 77, 999), hydazone (Hahn, e.f.; Itzhak, y.; Nishimura, s.; Johnson, N.; Pasternak, g.w.j.pharm.exper. therapeutics 1985, 235, 846-50), semicarbazone and thiosemicarbazone derivatives (Kolb, v.m.; Koman, a.; Neil, a. pharmaceutical res.1985, 6, 266-71). Naloxazone, the hydrazone of naloxone, is an irreversible, selective and long-acting antagonist of the mu-1 subclass of opioid receptors (pasernak, g.w.; Hahn, e.f.j.of med. chem.1980, 23, 674-6). Some derivatives are potent mu opioid antagonists while others are potent agonists.

The attachment of Naltrexamine (4) to a wide variety of other molecules via its primary amino group results in, for example, a wide range of non-equilibrium opioid agonists and antagonists, a fluorescent opioid receptor affinity label (LeBourdonnec, b.; El Kouhen, r.; Lunzer, m.m., Law, p.y.; Loh, h.h., porotoghese, p.s.; j.med.chem; 2000; 43; 2489-. (Sayre, L.M.; Larson, D.L.; Takemori, A.E.; Portoghese, P.S.J.Med.Chem.1984, 27, 1325), and a series of potent bivalent opioid antagonists (Erez, M.; Takemori, A.E.; Portoghese, P.S.J.Med.Chem 1982, 25, 847-849). Thus, the primary amino group of naltrexamine constitutes a suitable attachment site for the linker moiety.

5-fluoxetine 6N-methyl-fluoxetine paroxetine

The limited SAR of fluoxetine (5) has been disclosed in USP 4,214,081. N-methyl-fluoxetine (6) showed comparable potency and selectivity to fluoxetine for the inhibition of 5-hydroxytryptamine reuptake. Thus, attachment of the linker to the nitrogen atom of fluoxetine can result in retention of potency and selectivity of fluoxetine itself. However, the present description is not limited to the fluoxetine series of SSRIs. It is contemplated that the invention bivalent hybrid molecule of Med @, Wang, C.Z.; Johnson, K.M.; Tella, S.C.; Zhang, J.J.Am.Chem.2000, 122, 5393; Tamiz, A.P.; Johnson, K.M.; Kozikowski, A.P.J.Am.Chem.Soc.2000, 122, 5393; Tamiz, A.P.; Bandydhayy, B.C.; Zhang, J.J.; Flippen-Anderson, J.L.; Zhang, M.W.; Johnson, K.M.; Tella, S.koziki, A.16144, J.L. 1615, J.1624) may also be utilized with one or the other of the bivalent hybrid SSRis described by Paroxetine (Decvent, K.L.; Clissold, S.D.S.S.L.; 1991, Kozikowski, A.P.16144, J.D.D.S.S.S.S.S.5, J.1624).

Examples of linkers reported in the scientific literature include methylene (CH)₂)_nLinkers (Hussey, S.L.; Muddana, S.S.; Peterson, B.R.; J.Am.chem.Soc.2003; 125; 3692-O(-CH₂CH₂O-) n units of formula NH- (COCH) for linking opioid antagonists and agonists₂NH)_nCOCH₂CH₂CO-(NHCH₂CO)_nNH-aminoacetic acid oligomers ((a) Portoghese, P.S.; Rossesvalel, G.; Larson, D.L.; Yim, C.B.; Sayre, L.M.; Takemori, A.E.Life Sci.1982, 31, 1283-1286.(b) Portoghese, P.S.; Larson, D.L.; Sayre, L.M.; Yim, C.B.; Rosservale, G.; Tam, S.W.; Takemori, A.E.J.Med.Chem.1986, 29, 1855-1), hydrophilic diamines for linking together opioid peptides (Stepinski, J.; Zackazkoki, I.; Kazem-Bek, D.S.; Teik A.J.S.; Taikowski, A.S.S.S.S.S.S.&Protein res.1991, 38, 588-92), rigid double stranded DNA spacer arms (Paar, j.m.; harris, n.t.; holowka, d.; baird, b.j.immunol.2002, 169, 856-864), and a biodegradable linker poly (L-lactic acid) (Klok, h. -a.; hwang, j.j.; iyer, S.N.; stupp, s.i. macromolecules 2002, 35, 746-. Attachment of the tether to the antagonist may result in a favorable orientation of binding of the antagonist. The linker itself may or may not be biodegradable. The linker may take the form of a prodrug and is tunable for optimal release kinetics of the linked drug. The linker may be structurally flexible over its entire length or portions of the tether may be designed to be structurally constrained (Portoghese, p.s.; Ronsisvalle, g.; Larson, d.l.; Takemori, a.e.j.med.chem.1986, 29, 1650-.

In scheme 1 below, naltrexone (2) is used in the ligation reaction. As a result of the wittig reaction, the double bond replaces the carbonyl group in naltrexone. The end result is that fluoxetine is attached to the nalmefene molecule by means of a flexible methylene linker through the nalmefene double bond.

Scheme 1

Reductive amination of fluoxetine with omega-bromoaldehydes such as 11-bromoundecalaldehyde 6(n ═ 9) affords bromoamine 7(n ═ 9), which is preferably stored as the hydrobromide salt to prevent unwanted slow macrocyclization side effects by attacking the free amino group on the carbon with the bromine atom. Reaction of 7 with triphenylphosphine yielded an intermediate phosphonium salt, which upon reaction with butyllithium yielded the corresponding ylide 8(n ═ 9). The wittig reaction between 8 and the ketone group of naltrexone (2) gives the linked molecule 9 comprising fluoxetine units coupled to those now being nalmefene units. The expected mixture of cis, trans isomers with respect to the newly introduced double bond can be separated by standard chromatographic techniques. If racemic fluoxetine is used, a mixture of two optionally active diastereomers 9 will result due to the use of the single enantiomer 2 of naltrexone. Those skilled in the art of chemists will recognize that (CH)₂)₉The linker may vary in length and/or contain substituents by arising from different bromoaldehydes. Thus, the drug properties can be optimized. Under physiological conditions, molecule 9 is stable. The activity of the opioid antagonist is due to the covalently linked nalmefene units and not to the free nalmefene released by some cleavage reactions. Similarly, SSRI activity will be due to covalently linked fluoxetine units rather than free fluoxetine released by some cleavage reactions.

A similar reaction sequence can be used, wherein the bromoaldehyde is from an oligoethylene glycol as shown in scheme 2 below. For example, tetraethylene glycol (10n ═ 2) is converted to the bromide 11(n ═ 2), which is then oxidized under Swern conditions to the aldehyde 12(n ═ 2). Substitution of aldehyde 6 by aldehyde 12 in scheme 1 will result in a series of irreversibly linked molecules in which the linker is more hydrophilic than molecule 9. The production of the ylide in the oligoethylene glycol series and the subsequent wittig reaction are carried out with a temperature reduction to avoid β -elimination of the alkoxy group. If racemic fluoxetine is used, a mixture of the two optically active diastereomers 13 will result due to the use of the single enantiomer 2 of naltrexoneA compound (I) is provided. Those skilled in the art of chemists will recognize that by arising from the different bromo aldehydes 12, (OCH)₂CH₂)_nThe joint may vary in length. Thus, the drug properties can be optimized. Molecule 13 is stable under physiological conditions.

Scheme 2

In scheme 3, another linking method from tetraethylene glycol is illustrated as an example of a variety of oligoethylene glycols that can be used. Modifications to the chemistry of Sashiwa et al (Sashiwa, h.; Shigemasa, y.; Roy, r. macromolecules 2000, 33, 6913) can convert tetraethylene glycol to the acetal 14(n ═ 2) and subsequently to the aldehyde 15. Reductive amination of fluoxetine with aldehyde 15 gives fluoxetine derivative 16. Reduction of the nitride 16 to the amine 17 followed by reductive amination with naltrexone gives the molecule 18 in which the fluoxetine unit is irreversibly attached to the β -naltrexamine via a flexible oligoethyleneoxy unit (after separation of the α and β isomers). If racemic fluoxetine is used, a mixture of the two optically active diastereomers 18 will result due to the fact that the single enantiomer 2 of naltrexone is used. Those skilled in the art of chemists will recognize that by arising from the different oligoethylene glycols 10, (OCH)₂CH₂)_nThe joint may vary in length. Thus, the drug properties can be optimized. Molecule 18 is stable under physiological conditions.

Scheme 3

Scheme 4 illustrates the N-cyclopropyl group via nalmefene, fluoroSynthetic pathway for the linkage of sitagliptin and nalmefene. Readily available tert-butyldimethylsilyl-protected noroxymorphone (19) was synthesized from morphine (Ninan, a.; Sainsbury, m.tetrahedron 1992, 48, 6709-16), and then subjected to reductive amination with commercially available cyclopropanecarboxaldehyde (cyclopropanecarboxaldehyde)20(Aldrich, large trans) to give ester 21. Wittig methylation gives the ester 22, which is hydrolyzed to give the acid 23. Activation of the acid 23 with the appropriate carbodiimide and subsequent N-acetylation of the fluoxetine derivative 17 (scheme 3) gave 25 with Bu₄Deprotection of the NF gave new molecules 26. Those skilled in the art of chemists will recognize that by starting from the different aldehyde nitrides 15 in the synthesis of 17, (OCH)₂CH₂)_nThe joint may vary in length. Thus, the drug properties can be optimized. The molecule 26 should be stable under physiological conditions.

Alternatively, the ester 22 can be reduced to the aldehyde 24 using DIBAL at-78 ℃. After removal of the TBDMS protecting group, reductive amination of aldehyde 24 with amine 17 gives molecule 27. Those skilled in the art of chemists will recognize that by starting from the different aldehyde nitrides 15 in the synthesis of 17, (OCH)₂CH₂)_nThe joint may vary in length. Thus, the drug properties can be optimized. Molecule 27 should be stable under physiological conditions.

Scheme 4

If the Wittig methylenation step is omitted in the above sequence, an analogue of 26 called ketone 28 is formed, wherein the methylene group of 26 is substituted by a carbonyl group. The result is that in the form of compound 28, the naltrexone unit is via the flexible, hydrophilic (CH)₂CH₂O)_nThe linker is attached to the fluoxetine unit. Skilled chemists of ordinary skill in the artIt will be appreciated that by arising from the different aldehyde nitrides 15 in the synthesis of 17, (OCH)₂CH₂)_nThe joint may vary in length. Thus, the drug properties can be optimized. The molecule 28 is stable under physiological conditions.

Scheme 5 illustrates how fluoxetine can be attached to beta-naltrexamine using a combination of a linker called a flexible glycine-based linker 29 developed by Portoghese et al and an oligoethylene glycol linker used in the above scheme. Thus, activation of the carboxyl group at 29 with the appropriate carbodiimide followed by mono-condensation with β -naltrexamine gives the amide 30. Reactivation of 30 and subsequent condensation with amine 17 (scheme 3) gives molecule 31. Portoghese reported that symmetric amides from linker 29 and β -naltrexamine were potent mu-opioid receptor antagonists. Those skilled in the art will recognize that the linker unit 29, -NH- (COCH) may be modified by starting with a different glycine-based linker unit in the synthesis of 30₂NH)_n-1COCH₂CH₂CO-(NHCH₂CO)_nThe NH-linker may vary in length. Thus, the drug properties can be optimized. Molecule 31 is stable under physiological conditions.

Scheme 5

Reaction of bromide 7 (scheme 1) with Mg in anhydrous THF will yield Grignard 32, and reaction of Grignard 32 with the carbonyl group of naltrexone after separation of the two diastereomers produced in the newly formed chiral center yields addition compound 33. The addition compound 33 comprises a fluoxetine moiety linked to an N-cyclopropylmethyl-normorphine (normorphine) unit via a flexible methylene linker. Those skilled in the art of chemists will recognize that by starting from a different bromoaldehyde, (CH) in the synthesis of bromide 7₂)₉JointMay vary in length. Thus, the drug properties can be optimized. Molecule 33 is stable under physiological conditions.

Scheme 6

In all of the above schemes, it should be possible to use N-demethylfluoxetine (34), or any other derivative of fluoxetine, in place of fluoxetine. The resulting linked fluoxetine unit is the same as fluoxetine itself except that the methyl group of fluoxetine is replaced by a longer chain as the linker moiety. As illustrated in scheme 7, the intermediate fluoxetine secondary amino group can be protected by the application of an N- [2- (trimethylsilylethoxy) ] methyl (SEM) group when this is necessary due to the use of strong basic reagents or when chemoselectivity towards primary amino groups elsewhere in the molecule is desired (Zeng, Z.; Zimmerman, S.C. tetrahedron Lett.1988, 29, 5123).

Scheme 7

In another aspect, the invention relates to a pharmaceutical composition comprising an opioid antagonist as described above in combination with a compound that results in an increase in agonism of the melanocortin 3 receptor (MC3-R) or melanocortin 4 receptor (MC4-R) as compared to normal physiological conditions, or a linked molecule as described herein in combination with a physiologically acceptable carrier, diluent or excipient or a combination thereof.

The term "pharmaceutical composition" refers to a mixture of a compound of the present invention with other chemical components such as diluents or carriers. The pharmaceutical composition facilitates administration of the compound to an organism. Numerous techniques for administering compounds exist in the art including, but not limited to, oral, injection, aerosol, parenteral, and topical administration. Pharmaceutical compositions can also be obtained by reacting the compounds with inorganic or organic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, methanesulfonic acid, ethanesulfonic acid (ethanesulfonic acid), p-toluenesulfonic acid (p-tolenesulfonic acid), salicylic acid, and the like.

The term "carrier" defines a compound that facilitates incorporation of the compound into a cell or tissue. For example, dimethyl sulfoxide (DMSO) is a commonly used carrier because it facilitates the uptake of many organic compounds by cells or tissues of an organism.

The term "diluent" defines a compound dissolved in water that will solubilize the compound of interest and stabilize the biologically active form of the compound. Salts dissolved in buffer solutions are used as diluents in the art. A commonly used buffer solution is phosphate buffered saline because it mimics the salt conditions in human blood. Since buffer salts can control the pH of a solution at low concentrations, buffered diluents rarely alter the biological activity of a compound.

The term "physiologically acceptable" defines a carrier or diluent that does not abrogate the biological activity and properties of the compound.

The pharmaceutical compositions described herein may be administered to human patients per se or, as in combination therapy, in pharmaceutical compositions in which they are mixed with other active ingredients, or suitable carriers or excipients. Techniques for the formulation and administration of compounds for immediate use can be found in "Remington's Pharmaceutical Sciences," Mack Publishing co., Easton, PA, 18 th edition, 1990.

Suitable routes of administration may, for example, include oral, rectal, transmucosal or intestinal administration; parenteral delivery, including intramuscular, subcutaneous, intravenous, intraspinal injection, and intrathecal, direct intraventricular, intraperitoneal, intranasal, or intraocular injection.

Alternatively, the compounds may be administered locally rather than systemically, for example, by direct injection of the compound, often in the form of a long acting or sustained release formulation, into the rectum or heart region. Furthermore, the drug may be administered in a targeted drug delivery system, e.g., in liposomes coated with tissue-specific antibodies. Liposomes will be targeted by the organ and selectively taken up.

The pharmaceutical compositions of the invention may be manufactured in a manner that is itself known, for example, by means of conventional mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping or tableting methods.

Pharmaceutical compositions for use in accordance with the invention may thus be formulated in conventional manner using one or more physiologically acceptable carriers comprising excipients and auxiliaries which facilitate processing of the active compounds into preparations which can be used pharmaceutically. The appropriate formulation depends on the route of administration chosen. Any well-known techniques, carriers and excipients may be used as appropriate and understood in the art; for example, in Remington's Pharmaceutical Sciences, supra.

For injection, the agents of the invention may be formulated in aqueous solutions, preferably in physiologically suitable buffers such as Hanks's solution, Ringer's solution or physiological salt buffer. For transmucosal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art.

For oral administration, the compounds can be readily formulated by combining the active compounds with pharmaceutically acceptable carriers well known in the art. For oral ingestion by a patient to be treated, such carriers enable the compounds of the invention to be formulated as tablets, pills, dragees, capsules, liquids, gels, syrups, slurries, suspensions and the like. A pharmaceutical formulation for oral use is obtained by the following steps: one or more solid excipients are mixed with the pharmaceutical composition according to the invention, the resulting mixture is optionally ground, and after adding suitable auxiliaries, if desired, the mixture of granules is processed to obtain tablets or dragee cores. Suitable excipients are, in particular, fillers such as sugars, including lactose, sucrose, mannitol or sorbitol; cellulose preparations such as, for example, maize starch, wheat starch, rice starch, potato starch, gelatin, gum tragacanth, methyl cellulose, hydroxypropylmethyl-cellulose, sodium carboxymethylcellulose and/or polyvinylpyrrolidone (PVP). If desired, disintegrating agents such as cross-linked polyvinylpyrrolidone, agarose or alginic acid or a salt thereof such as sodium alginate may be added.

Dragee cores are provided with suitable coatings. For this purpose, concentrated sugar solutions may be used, which may optionally comprise gum arabic, talc, polyvinylpyrrolidone, carbopol gel, polyethylene glycol and/or titanium dioxide, lacquer solutions and suitable organic solvents or solvent mixtures. Dyestuffs or pigments may be added to the tablets or dragee coatings for identification or to characterize different combinations of active ingredient doses.

Pharmaceutical formulations which may be used orally include push-fit (push-fit) capsules made of gelatin, as well as soft, sealed capsules made of gelatin and a plasticiser such as glycerol or sorbitol. Push-fit capsules can contain the active ingredients mixed with fillers such as lactose, binders such as starches, and/or lubricants such as talc or magnesium stearate and, optionally, stabilizers. In soft capsules, the active compounds may be dissolved or suspended in suitable liquids, such as fatty oils, liquid paraffin, or liquid polyethylene glycols. In addition, stabilizers may be added. All formulations for oral administration should be present in a dosage form (dosage) suitable for such administration.

For buccal administration, the compositions may take the form of tablets or lozenges formulated in conventional manner.

For administration by inhalation, the compounds for use in accordance with the present invention are conveniently delivered in the form of an aerosol spray presentation from a compressed pack or nebulizer, using a suitable propellant, e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas.

In the case of a compressed aerosol, the dosage unit may be determined by providing a valve to deliver a metered amount. Capsules and cartridges of, for example, gelatin for use in an inhaler or insufflator may be formulated containing a powder mix of the compound and a suitable powder base such as lactose or starch.

The compounds may be formulated for parenteral administration by injection, for example by bolus injection or continuous infusion. Formulations for injection may be presented in unit dosage form, e.g., in ampoules or in multi-dose containers with an added preservative. The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulatory agents (formulating agents) such as suspending, stabilizing and/or dispersing agents.

Pharmaceutical preparations for parenteral administration comprise aqueous solutions of the active compounds in water-soluble form. In addition, suspensions of the active compounds can be prepared as appropriate oily injection suspensions. Suitable lipophilic solvents or vehicles include fatty oils such as sesame oil, or synthetic fatty acid esters such as ethyl oleate or triglycerides or liposomes. Aqueous injection suspensions may contain substances that increase the viscosity of the suspension, such as sodium carboxymethyl cellulose, sorbitol, or dextran. Optionally, the suspension may also contain suitable stabilizers or agents that increase the solubility of the compounds to allow for the preparation of highly concentrated solutions.

Alternatively, the active ingredient may be presented in powder form for constitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use.

The compounds may also be formulated in rectal compositions such as suppositories or retention enemas, e.g., containing conventional suppository bases such as cocoa butter or other glycerides.

In addition to the formulations described above, the compounds may be formulated as long acting formulations. Such long acting formulations may be administered by implantation (e.g., subcutaneously or intramuscularly) or by intramuscular injection. Thus, for example, the compounds may be formulated with suitable polymeric or hydrophobic materials (e.g., as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, e.g., as a sparingly soluble salt.

A pharmaceutically acceptable carrier for the hydrophobic compounds of the present invention is a cosolvent system comprising benzyl alcohol, a non-polar surfactant, a water-miscible organic polymer, and an aqueous phase. A commonly used co-solvent system is the VPD co-solvent system, which is 3% w/v benzyl alcohol, 8% w/v non-polar surfactant polysorbate 80, in a volume approximating that of anhydrous ethanol^TMAnd 65% w/v polyethylene glycol 300. Naturally, the proportions of the co-solvent system can be varied considerably without destroying its solubility and toxicity characteristics. Furthermore, the identity of the co-solvent components may vary: for example, other low toxicity non-polar surfactants may be used in place of POLYSORBATE 80^TM(ii) a The size of the polyethylene glycol fraction can vary; other biocompatible polymers, such as polyvinylpyrrolidone, may be substituted for the polyethylene glycol; other sugars or polysaccharides may be substituted for dextrose.

Alternatively, other hydrophobic drug compound delivery systems may be used. Liposomes and emulsions are well known examples of delivery vehicles or carriers for hydrophobic drugs. Certain organic solvents such as dimethyl sulfoxide can also be used, although often at the expense of greater toxicity. In addition, compounds may be delivered using sustained release systems, such as semipermeable matrices of solid hydrophobic polymers containing the therapeutic agent. Various sustained release materials have been identified and are well known to those skilled in the art. Depending on their chemical nature, sustained release capsules can release the compound from several weeks up to over 100 days. Depending on the chemical nature and biological stability of the therapeutic agent, additional strategies for stabilizing the protein may be used.

Many of the compounds used in the pharmaceutical combination of the present invention may be provided in the form of salts with pharmaceutically compatible counterions. Pharmaceutically compatible salts may be formed with a number of acids including, but not limited to, hydrochloric acid, sulfuric acid, acetic acid, lactic acid, tartaric acid, malic acid, succinic acid, and the like. Salts tend to be more soluble in aqueous or other protic solvents than their corresponding free acid or base forms.

Pharmaceutical compositions suitable for use in the present invention include compositions comprising the active ingredient in an amount effective to achieve its intended purpose. More specifically, a therapeutically effective amount means an amount of a compound effective to prevent, alleviate or ameliorate symptoms of a disease or prolong the survival of the subject being treated. Determination of a therapeutically effective amount is well within the ability of those skilled in the art, especially in light of the detailed description provided herein.

The precise formulation, route of administration, and dosage of The pharmaceutical compositions of The invention may be selected by The individual physician in view of The disease state of The patient (see, e.g., Fingl et al 1975 in "The pharmacological basis of Therapeutics", Ch.1 p.1). Typically, the dosage of the composition administered to the patient may range from about 0.5 to 1000mg/kg of the patient's body weight. The dose may be a single one or a series of two or more given over the course of one or more days, depending on the patient's needs. It is noted that for almost all of the specific compounds mentioned in this specification, human dosages for the treatment of at least some diseases have been established. Thus, in most cases, the invention will employ those same dosages, or dosages between about 0.1% and 500%, more preferably between about 25% and 250% of the established human dosage. Where no human dosage is established, as in the case of newly discovered pharmaceutical compounds, can be determined from ED₅₀Or ID₅₀Values, or other suitable values derived from in vitro or in vivo studies, such as qualitative by toxicity studies and efficacy studies in animals, to infer suitable human dosages.

Although the exact dosage will be determined on a drug-by-drug basis, in most cases some general guidelines regarding dosage (generation) may be set. The daily dosage regimen for an adult human patient may be, for example, an oral dose of the pharmaceutical composition of the invention or of each component thereof calculated as a pharmaceutically acceptable salt of the free base of between 0.1mg and 500mg, preferably between 1mg and 250mg, for example 5 to 200mg, or an intravenous, subcutaneous or intramuscular dose of each component of between 0.01mg and 100mg, preferably between 0.1mg and 60mg, for example 1 to 40mg of each component, the composition being administered 1 to 4 times daily. Alternatively, the compositions of the present invention may be administered by continuous intravenous infusion, preferably at doses of up to 400 mg/day of each component. Thus, the total daily dose of each component administered orally will typically be in the range of 1-2000mg and the total daily dose administered parenterally will typically be in the range of 0.1-400 mg. Suitably, the compound is administered for a sustained treatment period, for example, 1 week or more or months or years.

The amount and spacing of the doses may be adjusted individually to provide plasma levels of the active moiety sufficient to maintain a modulating effect, or to minimize the effective concentration (MEC). The MEC may vary for each compound, but it can be estimated from in vitro data. The dosage necessary to obtain a MEC will depend on the individual characteristics and the route of administration. However, HPLC assays or biological assays may be used to determine plasma concentrations.

The MEC value may also be used to determine the dose interval. The composition should be administered using a dosage regimen that maintains plasma levels above the MEC by a factor of 10-90%, preferably between 30-90%, and most preferably between 50-90%.

In the case of topical administration or selective absorption, the effective local concentration of the drug may not be correlated with plasma concentration.

The amount of the composition administered will, of course, depend on the subject being treated, the weight of the subject, the severity of the disease (affliction), the manner of administration and the judgment of the prescribing physician.

If desired, the composition may be presented in a pack or dispenser device, which may contain one or more units of a dosage form containing the active ingredient. The package may for example comprise a metal or plastic sheet, such as a blister pack (blister pack). The pack or dispenser device may be provided with instructions for application. The package or dispenser device may also be provided with an introduction associated with a container of a form designated by a governmental agency regulating the manufacture, use or sale of pharmaceuticals, which introduction reflects approval by the agency of a form of the pharmaceutical for human or veterinary administration. Such an introduction may be, for example, a label approved by the U.S. food and drug administration for a prescription drug, or an approved product insert (insert). Compositions comprising the compounds of the invention formulated in compatible pharmaceutical carriers can also be prepared and placed in appropriate containers and labeled for treatment of the indicated condition.

It will be well understood by those skilled in the art that many and various modifications may be made without departing from the spirit of the invention. Accordingly, it should be clearly understood that the forms of the present invention are illustrative only and are not intended to limit the scope of the present invention.

Some embodiments of the invention

Some embodiments of the invention are as follows:

in a first embodiment, the invention relates to a composition for affecting weight loss comprising a first compound and a second compound, wherein the first compound is an opioid antagonist and the second compound results in an increase in agonism of a melanocortin 3 receptor (MC3-R) or a melanocortin 4 receptor (MC4-R) as compared to normal physiological conditions.

In a second embodiment, the present invention is directed to the composition of the first embodiment, wherein the opioid antagonist antagonizes an opioid receptor in the mammal.

In a third embodiment, the present invention relates to the composition of the second embodiment, wherein said opioid receptors are selected from the group consisting of μ -opioid receptors (MOP-R), κ -opioid receptors and δ -opioid receptors.

In a fourth embodiment, the present invention is directed to the composition of the second embodiment, wherein the opioid antagonist antagonizes the μ -opioid receptor (MOP-R) in the mammal.

In a fifth embodiment, the present invention is directed to the composition of the first embodiment, wherein the opioid antagonist is selected from the group consisting of alvimopan, norbinaltorphimine, nalmefene, naloxone, naltrexone, methylnaltrexone, and nalorphine, and pharmaceutically acceptable salts or prodrugs thereof.

In a sixth embodiment, the present invention is directed to the composition of the first embodiment, wherein the opioid antagonist is a partial opioid agonist.

In a seventh embodiment, the present invention relates to the composition of the sixth embodiment, wherein said partial opioid agonist is selected from the group consisting of pentazine, buprenorphine, nalorphine, propiram and lefosidine.

In an eighth embodiment, the present invention is directed to the composition of the first embodiment, wherein the second compound triggers release of alpha-melanocyte stimulating hormone (alpha-MSH).

In a ninth embodiment, the present invention relates to the composition of the eighth embodiment, wherein said second compound increases extracellular 5-hydroxytryptamine concentration in the hypothalamus.

In a tenth embodiment, the present invention is directed to the composition of the ninth embodiment, wherein the second compound is selected from the group consisting of a selective 5-hydroxytryptamine reuptake inhibitor (SSRI), a 5-hydroxytryptamine 2C agonist, and a 5-hydroxytryptamine 1B agonist.

In an eleventh embodiment, the present invention relates to the composition of the tenth embodiment, wherein said second compound is selected from the group consisting of fluoxetine, fluvoxamine, sertraline, paroxetine, citalopram, escitalopram, sibutramine, duloxetine, and venlafaxine, and pharmaceutically acceptable salts or prodrugs thereof.

In a twelfth embodiment, the present invention relates to the composition of the first embodiment, wherein said second compound inhibits the expression of the AgRP gene or the production or release of wild grey protein-related protein (AgRP).

In a thirteenth embodiment, the present invention relates to the composition of the first embodiment, wherein said second compound inhibits the activity of an AgRP expressing neuron.

In a fourteenth embodiment, the present invention relates to the composition of the first embodiment, wherein said second compound inhibits the expression of the NPY gene or the production or release of neuropeptide y (NPY).

In a fifteenth embodiment, the present invention relates to the composition of the first embodiment, wherein said second compound inhibits the activity of neurons expressing NPY.

In a sixteenth embodiment, the present invention relates to the composition of the first embodiment, wherein said second compound is selected from the group consisting of an NPY Y1 receptor antagonist, a ghrelin antagonist and a leptin.

In a seventeenth embodiment, the present invention is directed to the composition of the first embodiment, wherein the second compound agonizes the NPY Y2 receptor.

In an eighteenth embodiment, the present invention is directed to the composition of the first embodiment, wherein the second compound is selected from the group consisting of a gamma aminobutyric acid (GABA) inhibitor, a GABA receptor antagonist and a GABA channel antagonist.

In a nineteenth embodiment, the present invention relates to the composition of the eighteenth embodiment, wherein the GABA inhibitor is a 5-HT1b agonist, which may be selected from sumatriptan, almotriptan, naratriptan, frovatriptan, rizatriptan, zomitriptan and elitriptan.

In a twentieth embodiment, the present invention relates to the composition of the eighteenth embodiment, wherein the GABA inhibitor inhibits the expression of the AgRP gene.

In a twenty-first embodiment, the present invention is directed to the composition of the eighteenth embodiment, wherein the GABA inhibitor inhibits the production or release of AgRP.

In a twenty-second embodiment, the present invention relates to the composition of the eighteenth embodiment, wherein the GABA inhibitor increases the expression of the POMC gene.

In a twenty-third embodiment, the present invention relates to the composition of the eighteenth embodiment, wherein the GABA inhibitor increases the production or release of α -MSH from pre-opio melanocortin (POMC) neurons.

In a twenty-fourth embodiment, the present invention relates to the composition of the eighteenth embodiment, wherein the GABA inhibitor increases the activity of POMC expressing neurons.

In a twenty-fifth embodiment, the present invention relates to the composition of the eighteenth embodiment, wherein said GABA inhibitor is topiramate.

In a twenty-sixth embodiment, the present invention is directed to the composition of the first embodiment, wherein the second compound is a dopamine reuptake inhibitor.

In a twenty-seventh embodiment, the present invention relates to the composition of the twenty-sixth embodiment, wherein said dopamine reuptake inhibitor is phentermine.

In a twenty-eighth embodiment, the present invention is directed to the composition of the first embodiment, wherein the second compound is a norepinephrine reuptake inhibitor.

In a twenty-ninth embodiment, the present invention relates to the composition of the twenty-eighth embodiment, wherein the norepinephrine reuptake inhibitor is selected from the group consisting of bupropion, thionisoxetine, and reboxetine.

In a thirty-second embodiment, the present invention relates to the composition of the first embodiment, wherein said second compound is a dopamine agonist.

In a thirty-first embodiment, the present invention relates to the composition of the thirty-second embodiment, wherein said dopamine agonist is selected from the group consisting of cabergoline, amantadine, lisuride, pergolide, ropinirole, pramipexole and bromocriptine.

In a thirty-second embodiment, the present invention is directed to the composition of the first embodiment, wherein the second compound is a norepinephrine releaser.

In a thirty-third embodiment, the present invention relates to the composition of the thirty-second embodiment, wherein said norepinephrine releasing agent is diethypropion.

In a thirty-fourth embodiment, the present invention is directed to the composition of the first embodiment, wherein the second compound is a combination of a dopamine reuptake inhibitor and a norepinephrine reuptake inhibitor.

In a thirty-fifth embodiment, the present invention relates to the composition of the thirty-fourth embodiment, wherein the second compound is selected from the group consisting of bupropion and mazindol.

In a thirty-sixth embodiment, the present invention is directed to the composition of the first embodiment, wherein the second compound is a combination of an SSRI and a norepinephrine reuptake inhibitor.

In a thirty-seventh embodiment, the present invention relates to the composition of the thirty-sixth embodiment, wherein the second compound is selected from sibutramine, venlafaxine, and duloxetine.

In a thirty-eighth embodiment, the present invention relates to the composition of the first embodiment, wherein said first compound is naltrexone and said second compound is fluoxetine.

In a thirty-ninth embodiment, the present invention relates to the composition of the thirty-eighth embodiment, wherein naltrexone is in a timed release formulation and fluoxetine is in an immediate release formulation.

In a fortieth embodiment, the present invention relates to a method of affecting weight loss, comprising identifying an individual in need thereof and treating the individual to antagonize opioid receptor activity and increase alpha-MSH activity.

In a forty-first embodiment, the present invention relates to the method of the forty-second embodiment, wherein said individual has a body mass index of more than 25.

In a forty-second embodiment, the present invention is directed to the method of the fortieth embodiment, wherein the activity of the opioid receptor is antagonized by administering an opioid receptor antagonist.

In a forty-third embodiment, the present invention is directed to the method of the forty-second embodiment, wherein the opioid receptor antagonist is a MOP receptor antagonist.

In a forty-fourth embodiment, the present invention is directed to the method of the forty-fourth embodiment, wherein the opioid receptor antagonist is selected from the group consisting of alvimopan, norbinaltorphimine, nalmefene, naloxone, naltrexone, methylnaltrexone, and nalorphine, and pharmaceutically acceptable salts or prodrugs thereof.

In a forty-fifth embodiment, the present invention is directed to the method of the forty-second embodiment, wherein said opioid receptor antagonist is a partial opioid agonist.

In a forty-sixth embodiment, the present invention is directed to the method of the forty-fifth embodiment, wherein said partial opioid agonist is selected from the group consisting of pentaazine, buprenorphine, nalorphine, propiram, and lofexidine.

In a forty-seventh embodiment, the present invention relates to from the forty-fifth to the forty-fifth embodiment, wherein the α -MSH activity is increased by administering a compound, wherein said compound triggers the release of α -MSH or increases the activity of neurons expressing α -MSH.

In a forty-eighth embodiment, the present invention is directed to the method of the forty-seventh embodiment, wherein the compound is a selective 5-hydroxytryptamine reuptake inhibitor (SSRI) or a specific 5-HT receptor agonist.

In a forty-ninth embodiment, the present invention is directed to the method of the forty-eighth embodiment, wherein the 5-HT receptor is selected from the group consisting of the 5-HT1b receptor and the 5-HT 2c receptor.

In a fifty-fourth embodiment, the present invention relates to the method of the forty-eighth embodiment, wherein the SSRI is selected from the group consisting of fluoxetine, fluvoxamine, sertraline, paroxetine, citalopram, escitalopram, sibutramine, duloxetine, and venlafaxine, and pharmaceutically acceptable salts or prodrugs thereof.

In a fifty-first embodiment, the present invention relates to the method of the forty-seventh embodiment, wherein the compound is a gamma aminobutyric acid (GABA) inhibitor.

In a fifty-second embodiment, the present invention relates to the method of the fifty-first embodiment, wherein the GABA inhibitor is a 5-HT1b receptor agonist.

In a fifty-third embodiment, the present invention relates to the method of the fifty-first embodiment, wherein the GABA inhibitor inhibits the expression of the AgRP gene.

In a fifty-fourth embodiment, the present invention relates to the method of the fifty-first embodiment, wherein the GABA inhibitor inhibits the production or release of AgRP.

In a fifty-fifth embodiment, the present invention relates to the method of the forty-eighth embodiment, wherein the 5-HT agonist inhibits NPY/AgRP/GABA neurons.

In a fifty-sixth embodiment, the present invention relates to the method of the fifty-first embodiment, wherein the GABA inhibitor inhibits the activity of neurons expressing AgRP.

In a fifty-seventh embodiment, the present invention relates to the method of the fifty-first embodiment, wherein the GABA inhibitor is topiramate.

In a fifty-eighth embodiment, the present invention relates to the method of the forty-seventh embodiment, wherein the compound is selected from the group consisting of a dopamine reuptake inhibitor, a norepinephrine reuptake inhibitor, a dopamine agonist, a norepinephrine releaser, a combination of a dopamine reuptake inhibitor and a norepinephrine reuptake inhibitor, and a combination of an SSRI and a norepinephrine reuptake inhibitor.

In a fifty-ninth embodiment, the present invention relates to the method of the fifty-eighth embodiment, wherein the compound is other than phentermine.

In a sixteenth embodiment, the present invention relates to the method of the fortieth embodiment, provided that the individual does not have Prader-Willi syndrome.

In a sixteenth embodiment, the present invention relates to the method of the fortieth embodiment, with the proviso that if the opioid receptor is antagonized using naltrexone, then the release of α -MSH is not stimulated by fluoxetine.

In a sixteenth embodiment, the present invention relates to the method of the forty fourth embodiment, wherein the treating step comprises administering to the individual a first compound and a second compound, wherein the first compound is an opioid antagonist and the second compound increases the activity of alpha-MSH.

In a sixty-third embodiment, the present invention is directed to the method of the sixty-second embodiment, wherein the first compound and the second compound are administered at about the same time.

In a sixty-fourth embodiment, the present invention is directed to the method of the sixty-third embodiment, wherein the first compound is administered before the second compound.

In a sixty-fifth embodiment, the present invention is directed to the method of the sixty-fourth embodiment, wherein the first compound is administered after the second compound.

In a sixteenth embodiment, the present invention relates to a method of increasing satiety in an individual, comprising identifying an individual in need thereof, and treating said individual to antagonize opioid receptor activity and increase alpha-MSH activity.

In a sixty-seventh embodiment, the present invention relates to the method of the sixty-sixth embodiment, wherein the treating step comprises administering to the individual a first compound and a second compound, wherein the first compound is an opioid antagonist and the second compound increases the activity of alpha-MSH.

In a sixty-eighth embodiment, the present invention is directed to the method of the sixty-seventh embodiment, wherein the first compound and the second compound are administered at about the same time.

In a sixty-ninth embodiment, the present invention is directed to the method of the sixty-seventh embodiment, wherein the first compound is administered before the second compound.

In a seventeenth embodiment, the present invention is directed to the method of the sixteenth embodiment, wherein the first compound is administered after the second compound.

In a seventy-first embodiment, the present invention relates to a method of increasing energy expenditure in an individual, comprising identifying an individual in need thereof and treating the individual to antagonize opioid receptor activity and increase alpha-MSH activity.

In a seventy-second embodiment, the present invention relates to the method of the seventy-first embodiment, wherein the treating step comprises administering to the individual a first compound and a second compound, wherein the first compound is an opioid antagonist and the second compound increases the activity of alpha-MSH.

In a seventy-third embodiment, the present invention is directed to the method of the seventy-second embodiment, wherein the first compound and the second compound are administered at about the same time.

In a seventy-fourth embodiment, the present invention is directed to the method of the seventy-second embodiment, wherein the first compound is administered before the second compound.

In a seventy-fifth embodiment, the present invention is directed to the method of the seventy-second embodiment, wherein the first compound is administered after the second compound.

In a seventy-sixth embodiment, the present invention relates to a method of suppressing appetite in an individual, the method comprising identifying an individual in need thereof and treating the individual to antagonize opioid receptor activity and increase alpha-MSH activity.

In a seventy-seventh embodiment, the present invention relates to the method of the seventy-sixth embodiment, wherein the treating step comprises administering to the individual a first compound and a second compound, wherein the first compound is an opioid antagonist and the second compound increases the activity of a-MSH.

In a seventy-eighth embodiment, the present invention is directed to the method of the seventy-seventh embodiment, wherein the first compound and the second compound are administered at about the same time.

In a seventy-ninth embodiment, the present invention is directed to the method of the seventy-seventh embodiment, wherein the first compound is administered before the second compound.

In an eighty-fourth embodiment, the present invention is directed to the method of the seventy-fourth embodiment, wherein the first compound is administered after the second compound.

In an eighty-first embodiment, the present invention relates to a method of affecting weight loss in an individual, the method comprising identifying an individual in need thereof and treating with a combination of naltrexone and fluoxetine if the individual does not have Prader-Willi syndrome or suffers from an eating disorder.

In an eighty-second embodiment, the present invention relates to the method of the eighty-first embodiment, wherein the individual has a BMI of greater than 30.

In an eighty-third embodiment, the present invention relates to the method of the eighty-first embodiment, wherein the individual has a BMI of greater than 25.

In an eighty-fourth embodiment, the present invention relates to the method of the eighty-first embodiment, wherein the naltrexone is in a time release formulation and the fluoxetine is in an immediate release formulation.

In an eighty-fifth embodiment, the present invention is directed to the method of the eighty-fourth embodiment, wherein the plasma concentration levels of both naltrexone and fluoxetine follow a similar concentration pattern.

In an eighty-sixth embodiment, the present invention relates to the method of the eighty-fourth embodiment, wherein the naltrexone and the fluoxetine are administered substantially simultaneously.

In an eighty-seventh embodiment, the present invention relates to the method of the eighty-fourth embodiment, wherein naltrexone is administered prior to the fluoxetine.

In an eighty-eighth embodiment, the present invention relates to the method of the eighty-fourth embodiment, wherein the naltrexone is administered after the fluoxetine.

Examples

The following examples are not limiting and are merely representative of various aspects of the present invention.

Example 1: combination of fluoxetine and naltrexone

Identifying an individual having a BMI in excess of 25. Each individual was instructed to take 20mg of fluoxetine tablet (PROZAC) on a daily basis in addition to 50mg of naltrexone tablet on a daily basis)。

Individuals were monitored over a period of months. It is recommended to adjust the dose so that each individual loses weight at a rate of 10% of the initial weight lost every six months. However, the rate of weight loss for each individual can be adjusted by the treating physician according to the individual's particular needs.

If the starting dose is not effective, the dose of fluoxetine can be increased by 20mg daily, but the total daily dose does not exceed 80 mg. The dose of each of fluoxetine or naltrexone can be reduced if the initial dose results in a faster rate of weight loss than described above.

Fluoxetine has a physiological half-life of about 9 hours, whereas the physiological half-life of naltrexone is about 1.5 hours. Thus, in some cases, it may be advantageous to administer one dose of fluoxetine daily in combination with two or three or more doses of naltrexone during a day. Naltrexone may also be in the form of a time release formulation in which the dose is administered once daily, but naltrexone gradually enters the bloodstream throughout the day or over the course of 12 hours.

Example 2: combination of fluoxetine and nalmefene:

identifying individuals having a BMI in excess of 25. Each individual was instructed to take 20mg of fluoxetine tablets (PROZAC) on a daily basis). In addition, each individual was injected intravenously, intramuscularly or subcutaneously with 1mL of a solution of 100 μ g of nalmefene in 1mL of saline.

If the starting dose is not effective, the dose of fluoxetine can be increased by 20mg daily, but the total daily dose does not exceed 80 mg. In addition, the dosage of nalmefene can be increased to 2mL of a 1mg solution of nalmefene in 1mL saline. The dose of each of fluoxetine or nalmefene can be reduced if the initial dose results in a faster weight loss than the rates described above.

Example 3: combination of fluoxetine and naloxone:

identifying individuals having a BMI in excess of 25. Each individual was instructed to take 20mg of fluoxetine tablets (PROZAC) on a daily basis). In addition, each individual was injected intravenously, intramuscularly or subcutaneously with 1mL of a solution of 400 μ g naloxone in 1mL saline.

If the starting dose is not effective, the dose of fluoxetine can be increased by 20mg daily, but the total daily dose does not exceed 80 mg. The dose of each of fluoxetine or nalmefene can be reduced if the initial dose results in a faster weight loss than the rates described above.

Example 4: combination of opioid antagonist and sibutramine:

identifying individuals having a BMI in excess of 25. Each individual was instructed to take nalmefene, naltrexone, or naloxone at the dosages set forth in examples 1-3. In addition, each individual was instructed to take orally 10mg of sibutramine once daily.

If the initial dose is not effective, the dose of sibutramine may be increased by 15mg daily. Dosages of sibutramine exceeding 15mg per day are not recommended. The dosage of each of sibutramine, nalmefene, naltrexone, or naloxone may be reduced if the initial dose results in a faster rate of weight loss than described above.

Example 5 combination of opioid antagonist and bupropion:

identifying individuals having a BMI in excess of 25. Each individual was instructed to take nalmefene, naltrexone, or naloxone at the dosages set forth in examples 1-3. In addition, each individual was instructed to take bupropion. A typical adult dose is 300 mg/day, 3 times daily. Dosing should start at 200 mg/day, twice daily, 100mg each time. Based on clinical response, this dose can be increased to 300 mg/day, 3 times daily, 100mg each time. The single dose does not exceed 150 mg.

Example 6: combination of opioid antagonist and phentermine:

identifying individuals having a BMI in excess of 25. Each individual was instructed to take nalmefene, naltrexone, or naloxone at the dosages set forth in examples 1-3. In addition, each individual was instructed to take 37.5mg of phentermine orally once daily.

Example 7: combination of naltrexone:

in a multicenter, randomized, blind, placebo-controlled clinical trial with 6 groups, the following drug combinations were tested:

group 1: fluoxetine 60mg po QD ganaxolone 50mg po QD

Group 2: fluoxetine 60mg po QD plus N-placebo po QD

Group 3: bupropion-SR 150mg po BID Gardnerella 50mg po QD

Group 4: bupropion-SR 150mg po BID plus N-placebo po QD

Group 5: p-placebo po BID Gardnasterone 50mg po QD

Group 6: p-placebo po BID plus N-placebo po QD

In any of the above groups, the dose of fluoxetine can be in the range of 6mg and 60mg, e.g., 6mg, 10mg, 12mg, 18mg, 20mg, 24mg, 30mg, 36mg, 40mg, 42mg, 45mg, 48mg, 54mg, and 60 mg. Bupropion can be administered in a dosage range between 30mg and 300mg, for example, 30mg, 40mg, 50mg, 60mg, 70mg, 80mg, 90mg, 100mg, 110mg, 120mg, 130mg, 140mg, 150mg, 160mg, 170mg, 180mg, 190mg, 200mg, 210mg, 220mg, 230mg, 240mg, 250mg, 260mg, 270mg, 280mg, 290mg, and 300 mg. Naltrexone may be administered in a dosage range between 5mg and 50mg, for example, 5mg, 10mg, 15mg, 20mg, 25mg, 30mg, 35mg, 40mg, 45mg and 50 mg.

In this study, subjects were evaluated as outpatients. All subjects in this trial received dietary guidance, behavior modification advice and guidance to increase their activities, indicating a weight loss regimen. Subjects were randomized to receive study drugs in various combinations.

After 16 weeks, subjects who crossed groups 5 and 6 were treated with fluoxetine galanthamine or bupropion SR galanthamine for an extended period of treatment time, which provided additional data on safety on combination therapy.

Initial endpoints were percent and absolute change in body weight from baseline at week 16. Secondary endpoints included weight loss at weeks 24, 36 and 48, number and proportion of subjects losing at least 5% and 10% of body weight (responder assay), changes in cardiovascular risk factors associated with obesity (total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, glucose and insulin), and waist circumference and safety and tolerability. Adverse events, laboratory parameters, vital signs, and Hospitalization Anxiety and Depression (HAD) levels were used to monitor safety and tolerability.

Example 8: dose response experiments:

prior to the experiment, 70 four-week-old, 22-30g male C57/B16J-mice (Jackson laboratory) were sham-injected daily with 0.1mL of 0.9% saline (pH7.4) for one week. 1 day before the start of the experiment, animals were weighed and randomly assigned to one of 1 of 7 individual weight-matched dose groups (0, 1.5, 3, 5.5, 10, 18 and 30 mg/kg; fluoxetine n ═ 10/group; 0, 1.5, 3, 5.5, 10, 18 and 30 mg/kg; naltrexone n ═ 3/group). Food was removed between 4:30 and 5:30pm 1 day before the start of the experiment. Animals received either a 0.3mL bolus (fluoxetine) or a 0.1mL bolus (naltrexone) by intraperitoneal injection between 9-10:30am, providing food immediately after injection. On each test day3 animals/group received injections (i.e., 3 rounds of 3 animals/group, 1 round of 1 animal/group). Food was weighed 1, 2, 4, 8 and 24 hours after injection. Absorption ± SEM of accumulated food was calculated and analyzed using Prizm. These numbers of SEMs were found to be between 0.0041 and 0.26. The dose was logarithmically transformed and fitted to a sigmoidal curve, and food absorption was expressed as the proportion of food absorption in saline-treated animals. From this curve, the EC for each drug at each time point was determined₅₀。

Similar steps to those above were then carried out using fluvoxamine and nalmefene and bupropion and naltrexone.

The results are shown in the table below.

Fluoxetine	0.36	0.57	0.68	0.76	1.05
Fluoxetine	0.36	0.57	0.68	0.76	1.05	Naltrexone + fluoxetine	0.070	0.26	0.72	0.95	1.04

Example 9: electrophysiological data:

to test the hypothesis that drugs selectively activate POMC neurons, we used lines of transgenic mice that express green fluorescent protein (EGFP, Clontech) under the transcriptional control of the mouse POMC genomic sequence that includes the region between-13 kb and-2 kb required for precise neuronal expression. Bright green fluorescence (509nm) was observed in two CNS regions where POMC was produced: ARC and nuclei of solitary tracts. Under the stimulation of ultraviolet light (450-.

Coronal sections of 200 μm thickness were excised from ARC of four-week-old male POMC-EGFP mice. The sections were kept at 35 ℃ in Krebs solution (NaCl (126mM), KCl (2.5mM), MgCl₂91.2mM)、CaCl₂.2H₂O(2.4mM)、NaH₂PO₄.H₂O(1.2mM)、NaHCO₃(21.4mM), glucose (11.1mM) and 95% O before recording₂And 5% CO₂Saturation was 1 hour. Recordings were made in Krebs at 35 ℃. Sections can be viewed on Axioskop FS2 plus (Zeiss) with standard infrared light and using epifluorescence through FITC (longpass) filter set. POMC-EGFP neuronal sections in the hypothalamus had resting membrane potentials of-40 to-45 mV and showed frequent spontaneous action potentials. Recordings of cell attachment from fluorescent neurons were performed using an Axomatch 200B amplicon (Axon Instruments) and Clampex 8(Axon Instruments). The action potential frequency was determined using the event detection program (Mini Analysis; Synaptoft Inc., Decatur, Ga.). The drug was applied in a water bath for 3 minutes.

The data was analyzed by determining an average discharge rate of 500 seconds prior to drug addition and analyzing the treatment against this frequency (i.e., normalizing the discharge rate to the pretreatment frequency). The ratio of the combinations listed is the ratio of the effect of naltrexone binding to the POMC activator relative to the effect of naltrexone alone (i.e., naltrexone imparts additional potency to the POMC activator). Only the mean effect of the drug is listed.

Fenfluramine 2X increase (n ═ 6)

Fenfluramine + naltrexone 5.2X (n ═ 8)

Fluoxetine 3X (n ═ 1)

Fluoxetine + naltrexone 1.2X (n ═ 1)

Dopamine 11X (n ═ 9)

Dopamine decanaltrexone 1.5X (n ═ 3)

Naltrexone alone has a strong (7X) but variable effect. Many cells do not respond to naltrexone alone, but have a marked response to combination therapy. Heisler et al (Science 297 (5581): 609-11(2002)) showed 200% effect of fenfluramine alone.

Medicine	Dosage form	Effect (%)	Medicine	Dosage form	Effect (%)	Ratio of
Medicine	Dosage form	Effect (%)	Medicine	Dosage form	Effect (%)	Ratio of	Naltrexone	1μM	29650	Naltrexone + fenfluramine	1μM+20μM	15080	0.51
Naltrexone	1μM	2200	Naltrexone + fenfluramine	1μM+20μM	11440	520	Naltrexone	1μM	29650	Naltrexone + fenfluramine	1μM+20μM	15080	0.51
Naltrexone	1μM	2200	Naltrexone + fenfluramine	1μM+20μM	11440	520	Naltrexone	1μM	2500	Naltrexone + fenfluramine	1μM+20μM	856	0.34
Naltrexone	1μM	417	Naltrexone + fenfluramine	1μM+20μM	5700	13.67	Naltrexone	1μM	2500	Naltrexone + fenfluramine	1μM+20μM	856	0.34
Naltrexone	1μM	417	Naltrexone + fenfluramine	1μM+20μM	5700	13.67	Naltrexone	1μM	177	Naltrexone + fenfluramine	1μM+20μM	430	2.43
Naltrexone	1μM	200	Naltrexone + fenfluramine	1μM+20μM	2933	14.67	Naltrexone	1μM	177	Naltrexone + fenfluramine	1μM+20μM	430	2.43
Naltrexone	1μM	200	Naltrexone + fenfluramine	1μM+20μM	2933	14.67	Naltrexone	1μM	700	Naltrexone + fenfluramine	1μM+20μM
Naltrexone	1μM	900	Naltrexone + fenfluramine	1μM+20μM	1831	2.03	Naltrexone	1μM	700	Naltrexone + fenfluramine	1μM+20μM
Naltrexone	1μM	900	Naltrexone + fenfluramine	1μM+20μM	1831	2.03	Naltrexone	1μM	2273	Naltrexone + fenfluramine	1μM+20μM
Naltrexone	1μM	300	Naltrexone + fenfluramine	1μM+20μM	920	3.07	Naltrexone	1μM	2273	Naltrexone + fenfluramine	1μM+20μM

Claims

1. A composition for affecting weight loss comprising a first compound and a second compound, wherein the first compound is an opioid antagonist and the second compound is selected from the group consisting of: a dopamine reuptake inhibitor, a norepinephrine reuptake inhibitor, an SSRI, a combination of a dopamine reuptake inhibitor and a norepinephrine reuptake inhibitor, and a combination of an SSRI and a norepinephrine reuptake inhibitor.

2. The composition of claim 1, wherein the opioid antagonist antagonizes an opioid receptor selected from the group consisting of the μ -opioid receptor (MOP-R), the kappa-opioid receptor, and the delta-opioid receptor.

3. The composition of claim 2, wherein the opioid antagonist is a μ -opioid receptor (MOP-R) antagonist.

4. The composition of claim 1 wherein the opioid antagonist is selected from the group consisting of alvimopan, norbinaltorphimine, nalmefene, naloxone, naltrexone, methylnaltrexone, and nalorphine, and pharmaceutically acceptable salts or prodrugs thereof.

5. The composition of claim 4, wherein the opioid antagonist is naltrexone or a pharmaceutically acceptable salt thereof.

6. The composition of any one of claims 1 to 5, wherein the second compound is a dopamine reuptake inhibitor or a norepinephrine reuptake inhibitor.

7. The composition of claim 6, wherein said dopamine or norepinephrine reuptake inhibitor is selected from the group consisting of bupropion, thionisoxetine, reboxetine, and radafaxine.

8. The composition of claim 7, wherein the second compound is bupropion or a pharmaceutically acceptable salt thereof.

9. The composition of any one of claims 1 to 5, wherein the second compound is an SSRI.

10. The composition of claim 9, wherein the SSRI is selected from the group consisting of fluoxetine, fluvoxamine, sertraline, paroxetine, citalopram, escitalopram, sibutramine, duloxetine, and venlafaxine, and pharmaceutically acceptable salts or prodrugs thereof.

11. The composition of claim 10, wherein the SSRI is fluoxetine or a pharmaceutically acceptable salt thereof.

12. The composition of any one of claims 1 to 5, 7, 8, 10, or 11, wherein the first compound and the second compound are a single oral dosage form.

13. The composition of claim 12, wherein the single oral dosage form further comprises a pharmaceutically acceptable excipient, diluent or carrier.

14. The composition of any one of claims 5 to 11, wherein the amount of naltrexone or pharmaceutically acceptable salt thereof is about 5mg to about 50mg per day.

15. The composition of any one of claims 8 to 11, wherein said amount of bupropion or pharmaceutically acceptable salt thereof is from about 30mg to about 500mg per day.

16. The composition of claim 12, wherein the single oral dosage form is a sustained release dosage form.

17. The composition of claim 13, wherein the single oral dosage form is a sustained release dosage form.

18. Use of a combination of a first compound and a second compound in the manufacture of a medicament for affecting weight loss in an individual in need thereof, wherein the first compound is an opioid antagonist and the second compound is selected from the group consisting of: a dopamine reuptake inhibitor, a norepinephrine reuptake inhibitor, an SSRI, a combination of a dopamine reuptake inhibitor and a norepinephrine reuptake inhibitor, and a combination of an SSRI and a norepinephrine reuptake inhibitor.

19. The use of claim 18, wherein the weight loss activity of the first and second compounds is synergistic compared to the same amount of either compound administered alone.

20. The use of claim 18, wherein the first compound is an opioid receptor antagonist.

21. The use of claim 20, wherein the opioid receptor antagonist is a μ -opioid receptor (MOP-R) antagonist.

22. The use of claim 18 wherein the opioid antagonist is selected from alvimopan, norbinaltorphimine, nalmefene, naloxone, naltrexone, methylnaltrexone, and nalorphine, and pharmaceutically acceptable salts or prodrugs thereof.

23. The use of claim 22, wherein the opioid antagonist is naltrexone or a pharmaceutically acceptable salt thereof.

24. The use of any one of claims 18 to 23, wherein the second compound is a dopamine reuptake inhibitor or a norepinephrine reuptake inhibitor.

25. The use of claim 24, wherein the dopamine or norepinephrine reuptake inhibitor is selected from the group consisting of bupropion, thionisoxetine, reboxetine, and radafaxine.

26. The use of claim 25, wherein the second compound is bupropion or a pharmaceutically acceptable salt thereof.

27. The use of claim 26, wherein the composition further comprises zonisamide or a pharmaceutically acceptable salt thereof.

28. The use of any one of claims 18 to 23, wherein the second compound is an SSRI.

29. The use of claim 28, wherein the SSRI is selected from the group consisting of fluoxetine, fluvoxamine, sertraline, paroxetine, citalopram, escitalopram, sibutramine, duloxetine, and venlafaxine, and pharmaceutically acceptable salts or prodrugs thereof.

30. The use of claim 29, wherein the SSRI is fluoxetine or a pharmaceutically acceptable salt thereof.

31. The use of any one of claims 18 to 23, 26, 27 or 30, wherein the individual is identified or diagnosed as having overweight or obesity.

32. The use of any one of claims 18 to 23, 26, 27 or 30, wherein the subject does not have depression, Prader-Willi syndrome, or suffer from eating disorders.

33. The use of claim 31, wherein said amount of said first compound, said amount of said second compound, or both, is adjusted as needed to treat overweight or obesity in said subject.

34. The use of any one of claims 18 to 23, 26, 27, or 30, wherein said amount of said first compound, said amount of said second compound, or both are adjusted such that said individual loses weight at a rate of 10% of initial weight loss every six months.

35. The use of any one of claims 18 to 23, 26, 27, or 30, wherein said first and second compounds are effective to increase satiety in said individual.

36. The use of any one of claims 18 to 23, 26, 27 or 30, wherein the first and second compounds are effective to suppress appetite in the individual.

37. The use of any one of claims 18 to 23, 26, 27 or 30, wherein the individual is treated, the treatment further comprising the formulation of a dietary regimen and increased activity.

38. The use of any one of claims 18 to 23, 26, 27 or 30, wherein the medicament is administered at least once a day.

39. The use of any one of claims 18 to 23, 26, 27 or 30, wherein the subject has 25kg/m²Body mass index above.

40. The use of any one of claims 18 to 23, 26, 27 or 30, wherein the subject has 30kg/m²Body mass index above.

41. The use of any one of claims 18 to 23, 26, 27 or 30, wherein the medicament is administered for a period of at least 16 weeks.

42. The use of any one of claims 18 to 23, 26, 27 or 30, wherein the medicament is administered for a period of at least 24 weeks.

43. The use of any one of claims 18 to 23, 26, 27 or 30, wherein the medicament is administered until the individual has achieved at least 5% weight loss or the individual's body mass index is reduced to less than 25kg/m²。

44. The use of any one of claims 18 to 23, 26, 27 or 30, wherein the first compound and the second compound are formulated such that the first compound can be administered before, simultaneously with, or after the second compound.

45. The use of any one of claims 18 to 23, 26, 27 or 30, wherein said first compound and said second compound are in a single oral dosage form.

46. The use of claim 45, wherein the single oral dosage form further comprises a pharmaceutically acceptable excipient, diluent or carrier.

47. The use of any one of claims 23, 25-27, 29, or 30, wherein the amount of naltrexone or pharmaceutically acceptable salt thereof is in the range of about 5mg to about 50mg per day.

48. The use of any one of claims 26, 27, 29 or 30, wherein said amount of bupropion or pharmaceutically acceptable salt thereof is from about 30mg to about 500mg per day.

49. The use of any one of claims 23, 25-27, 29, or 30, wherein said naltrexone or pharmaceutically acceptable salt thereof is a sustained release naltrexone.

50. The use of any one of claims 26, 27, 29 or 30 wherein said bupropion or pharmaceutically acceptable salt thereof is a sustained release bupropion.

51. The use of claim 47, wherein said naltrexone or pharmaceutically acceptable salt thereof is a sustained release naltrexone.

52. The use of claim 48, wherein said bupropion or pharmaceutically acceptable salt thereof is a sustained release bupropion.

53. The use of claim 18, wherein said first compound is naltrexone or a pharmaceutically acceptable salt thereof, and said second compound is bupropion or a pharmaceutically acceptable salt thereof.

54. The use of claim 53, wherein the amount of said naltrexone or pharmaceutically acceptable salt thereof is in the range of about 5mg to about 50mg per day.

55. The use of claim 54, wherein said bupropion or pharmaceutically acceptable salt thereof is in an amount of about 30mg to about 500mg per day.

56. The use of any one of claims 53 to 55 wherein the naltrexone or pharmaceutically acceptable salt thereof is a sustained release naltrexone.

57. The use of claim 56, wherein said bupropion or pharmaceutically acceptable salt thereof is a sustained release bupropion.

58. The composition according to claim 1, wherein said first compound is naltrexone or a pharmaceutically acceptable salt thereof, and said second compound is bupropion or a pharmaceutically acceptable salt thereof.

59. The composition of claim 58, wherein said naltrexone or pharmaceutically acceptable salt thereof is in an amount of about 5mg to about 50mg per day.

60. The composition of claim 59, wherein the amount of said bupropion or pharmaceutically acceptable salt thereof is from about 30mg to about 500mg per day.

61. The composition of any one of claims 58 to 60, wherein said naltrexone or pharmaceutically acceptable salt thereof is a sustained release naltrexone.

62. The composition of claim 61, wherein said bupropion or pharmaceutically acceptable salt thereof is a sustained release bupropion.