RU2828667C1 - Analgesic agent - Google Patents

Abstract

FIELD: medicine; pharmacology.

SUBSTANCE: invention relates to the use of oxalate (Z)-O-(2-morpholinoethyl)oxime of 4-benzoylpyridine (“ГИЖ-298”) as an analgesic agent.

EFFECT: wider range of analgesic agents, including effective in somatic, visceral pain, and affecting the spinal flexor reflex, and the possibility of using “ГИЖ-298” as an analgesic and in patients suffering from convulsive syndromes, which are a contraindication for the use of certain analgesics.

1 cl, 6 tbl, 5 ex

Description

The claimed invention relates to the field of medicine, in particular pharmacology, namely the use of oxalate (Z)-O-(2-morpholinoethyl)oxime 4-benzoylpyridine (GIZH-298) as a means with an analgesic effect, which can be used to create an analgesic drug based on it.

According to the Russian Society for the Study of Pain, published in 2017, the prevalence of chronic pain syndromes in Russia ranges from 13.8 to 56.7%, with an average of 34.3 cases per 100 people [Rachin A.P., Sharov M.N., Averchenkova A.A. et al. RMZh. 2017; 9:625-31]. The prevalence of chronic pain in older age groups is 27-86%; the duration of its course, according to various estimates, ranges from 3-6 to 25-30 years; in terms of pathogenetic origin, musculoskeletal pain (40%) and peripheral neuropathic pain (40%) predominate [Clinical guidelines. Chronic pain in elderly and senile patients. The link is active as of 01.02.2024. https://cr.minzdrav.gov.ru/schema/616_1]. Moreover, pain syndromes occur in 85.7% of patients who have had COVID-19 [Bakilan F., Gökmen İ.G., Ortanca B. et al. Int. J. Clin. Pract. 2021; 75(11): e14734]. In people with pre-existing musculoskeletal pain, the period of remission decreases after COVID-19, the number and severity of exacerbations increases [Putilina M.V., Mutovina Z.Yu., Kurushina O.V. et al. Zh. Nerv. i Psychiatrist im. S.S. Korsakov. 2022; 122(1): 84-90; Disser N.P., De Micheli A.J., Schonk M.M. et al. J. Bone Joint Surg. Am. 2020; 102(14): 1197-204].

Nonsteroidal anti-inflammatory drugs (NSAIDs) are first-line drugs for the treatment of musculoskeletal pain. They are prescribed in all cases of moderate to severe musculoskeletal pain in the absence of absolute contraindications. The use of NSAIDs may be accompanied by the development of serious "class-specific" side effects, primarily from the gastrointestinal tract and cardiovascular system, which limits their prescription or duration of use [Nasonov E.L., Yakhno N.N., Karateev A.E. et al. Scientific and Practical Rheumatology. 2016; 54(3): 247-65].

The first line of pharmacotherapy for neuropathic pain includes antidepressants and anticonvulsants, the second and third lines include opioid analgesics, topical drugs, and botulinum toxin type A. In addition, B vitamins and their complexes, alpha-lipoic acid, and acetyl-L-carnitine are used as additional pharmacotherapy agents [Davydov O.S., Yakhno N.N., Kukushkin M.L. et al. Russian Journal of Pain. 2018; 58(4): 5-41]. However, the effectiveness of pharmacotherapy for neuropathic pain syndromes remains low - less than 50% [Baron R., Maier C., Attal N. et al. Pain. 2017; 158(2): 261-72].

3,4,5,6-tetrahydro-5-methyl-1-phenyl-1H-2,5-benzoxazocine hydrochloride (nefopam) is known - a drug that exhibits an analgesic effect, suppresses the nociceptive flexion reflex, pain and chills in the postoperative period, and is used for pain syndrome of various etiologies and intensities. However, nefopam is contraindicated in epilepsy and diseases accompanied by increased seizure readiness [RLS. Link active on 02/01/2024. https://www.rlsnet.ru/active-substance/nefopam-1144#pharmakologicheskoe-deistvie].

The need for long-term pharmacotherapy of chronic pain syndromes, in some cases insufficient pain relief and drug resistance, the development of tolerance to the action of analgesics and the side effects of existing drugs determine the advisability of developing new means of pharmacotherapy of pain syndromes.

The objective of the present invention was to find an agent that reduces the severity of somatic and visceral pain, suppresses the nociceptive reflex and has no contraindications for convulsive syndromes. The problem was solved by using a derivative of 4-benzoylpyridine oxime GIZh-298 (oxalate (Z)-O-(2-morpholinoethyl)oxime 4-benzoylpyridine) as an analgesic. GIZh-298 is a compound with anticonvulsant activity and is being developed as a treatment for epilepsy and paroxysmal conditions [Patent of the Russian Federation 2643091; 31.01.2018. Bulletin No. 4]. The prototype of the present invention is nefopam. Unlike nefopam, GIZh-298 has anticonvulsant activity, so its use will not be limited in convulsive syndromes. The technical result is an expansion of the arsenal of painkillers, including those effective for somatic, visceral pain and those affecting the spinal flexor reflex, and the possibility of using GIZH-298 as an analgesic and in patients suffering from convulsive syndromes, which are a contraindication for the use of some analgesics. GIZH-298 exhibits an analgesic effect on pain models of different etiologies, which is explained by the examples below, but is not limited to them.

Example 1

Somatic pain during surgical incisions (injuries) is reproduced by the formalin pain technique [Dubuisson D., Denis S.G. Pain 1977; 4: 161-174; Voronina T.A., Guzevatykh L.S. Methodical recommendations for studying the analgesic activity of drugs. Guidelines for conducting preclinical studies of drugs. Part one. Moscow: Grif i K, 2012. pp. 197-218]. The formalin test is used in various modifications: when introducing a formalin solution of different concentrations into the metatarsus area (most often a 2-5% solution), the experiment is mainly carried out on mice and rats [Voronina T.A., Guzevatykh L.S. 2012]. In the formalin test, spontaneous pain behavior of animals is characterized by two phases. The first phase, which lasts for the first 5 minutes, is caused by the effect of formalin on the TRPA1 ion channel of afferent neurons, the second phase is delayed in time, and its mechanism is associated with the developing inflammatory reaction and central sensitization, it is usually recorded starting from the 20th minute after the introduction of the formalin solution [McNamara C.R., Mandel-Brehm J., Bautista D.M. et al. P. Natl. Acad, of Sci. USA. 2007; 104(33): 13525-30; Fisher M, Carli G., Raboisson P., Reeh P. Pain. 2014; 155(3): 511-21]. Between these two phases, an interphase is observed, during which a minimal manifestation of pain reaction is recorded in animals and which is used to differentiate the first and second phases of formalin pain. The decrease in the pain response during the interphase is explained by the result of hyperpolarization and temporary inactivation of neurons, the subsequent increase in excitability of which and the centrifugal spread of formalin in the skin causes the second phase of the pain response [Fisher M. et al. 2014]. Most often, minimal manifestations of the pain response of animals are recorded approximately 10 minutes after the introduction of formalin solution into the paw [Tjolsen A., Berge O.G., Hunskaar S. et al. Pain, 1992; 51:5-17; Fisher M. et al. 2014].

The experiment was performed on white male ICR mice weighing 24-28 g from the nursery of the Stolbovaya branch of the Federal State Budgetary Institution of Science “Scientific Center for Biomedical Technologies of the Federal Medical and Biological Agency of Russia”. The work was organized and carried out in accordance with GOST 33216-2014 “Guidelines for the Maintenance and Care of Laboratory Animals. Rules for the Maintenance and Care of Laboratory Rodents and Rabbits”, GOST 33215-2014 “Guidelines for the Maintenance and Care of Laboratory Animals.

Formalin test. In our experiment, we used 5% formalin solution, which was injected in a volume of 20 μl into the metatarsus area of mice using a Hamilton syringe; the test modification used simulates severe formalin pain. Immediately after the injection of 5% formalin solution into the hind paw of mice, the time (seconds) of mouse behavior indicating pain was recorded for 30 minutes using Real Timer software (procedural timer, NPK Open Science, Russia): the paw was licked, shaken, raised. The total duration of mouse behavior indicating pain was calculated in the following time intervals after the injection of the formalin solution into the paw: 0-5 minutes, 6-10 minutes, 11-15 minutes, 16-20 minutes, 21-25 minutes, 26-30 minutes. GIZh-298 was administered orally once in doses of 10, 20, 40 and 60 mg/kg 1 hour before the introduction of formalin solution into the paw of the animals. The control group of animals was orally administered an equivalent volume of solvent - physiological sodium chloride solution (10 ml/kg).

It was found that in the first phase of formalin pain (0-5 minutes), the duration of pain behavior in mice of the control group, which were orally administered the solvent, was 281.4 seconds. GIZh-298 significantly reduced the duration of pain behavior in mice in the first phase of formalin pain: at a dose of 10 mg/kg - by 14.5%, at a dose of 40 mg/kg - by 13.0%, at a dose of 60 mg/kg - by 22.5% (Table 1). GIZh-298 had a dose-dependent effect on the pain behavior of animals in the interphase, increasing the duration of inactivation of nociceptive neurons. Thus, if when administered at a dose of 10 mg/kg, GIZh 298 did not significantly affect the pain behavior of mice in the time intervals of 6-10 minutes, 11-15 minutes and 16-20 minutes after the administration of the formalin solution, then when the compound was administered at doses of 20 and 40 mg/kg, a significant decrease in the duration of pain behavior of mice was recorded in the time interval from 16 to 20 minutes after the administration of the algogen, which amounted to 56.8% and 87.3%, respectively, compared to the control group. GIZh-298 at a dose of 60 mg/kg significantly reduced the duration of pain behavior of mice from 11 to 15 minutes and from 16 to 20 minutes after the administration of the formalin solution by 84.8% and 92.5%, respectively, compared to the control group (Table 1).

The pain behavior of animals was recorded for 30 minutes, during the last 10 minutes of which (from 21 to 30 minutes) the initial stage of the second phase of formalin pain was recorded. It was found that GIZh-298 at a dose of 60 mg/kg and 40 mg/kg significantly (with paired comparison of groups by the Mann-Whitney criterion) reduced the duration of pain behavior in mice compared to the control group: at a dose of 60 mg/kg - by 77.1% from 21 to 25 minutes, at a dose of 40 mg/kg - by 44.9% from 26 to 30 minutes after the introduction of formalin solution into the paw of animals. The decrease in the severity of pain in mice from 20 to 30 minutes after the administration of formalin solution when they were given GIZh-298 at a dose of 40 and 60 mg/kg is a consequence of the manifestation of the effect of the compound in the acute phase of formalin pain and the interphase (Table 1).

Thus, in the formalin test in mice (when recording the behavior of mice for 30 minutes after the introduction of a 5% formalin solution), GIZh-298, when administered orally once in doses of 10-60 mg/kg, exhibits a dose-dependent analgesic effect.

Example 2

Subcutaneous administration of small doses of the TRPV1 agonist capsaicin into the hind paw of mice induces an acute nociceptive response [Koivisto A.P., Belvisi M.G., Gaudet R., Szallasi A. Nat. Rev. Drug Discov. 2022; 21(1): 41-59], which is used as a test (capsaicin test) to assess the analgesic effect of compounds.

The experiment was performed on white male ICR mice weighing 24-26 g from the nursery of the Stolbovaya branch of the Federal State Budgetary Scientific Institution “Scientific Center for Biomedical Technologies of the Federal Medical and Biological Agency of Russia”. The work was organized and carried out in accordance with GOST 33216-2014 “Guidelines for the Maintenance and Care of Laboratory Animals. Rules for the Maintenance and Care of Laboratory Rodents and Rabbits”, GOST 33215-2014 “Guidelines for the Maintenance and Care of Laboratory Animals.

Capsaicin test. Mice were placed in individual transparent plexiglass chambers on a stand with a mirror underneath to provide a view of the hind limbs through the chamber floor. After the adaptation period, 1.6 μg of capsaicin (Sigma Aldrich, USA) [Sakurada T., Katsumata K., Tan-No K. et al. Neuropharmacol. 1992; 31(12): 1279-1285] diluted in 20 μl of saline and ethanol (9:1, v/v) were injected subcutaneously into the metatarsal region of the left hind paw using a Hamilton syringe. Starting immediately after the introduction of the capsaicin solution, the time (seconds) of pain-indicating behavior of the mice was recorded for 5 minutes using RealTimer software (procedural timer) (Open Science Research and Production Corporation, Russia): the paw was licked, shaken, and raised. GIZh-298 was administered orally once in doses of 40 and 60 mg/kg 1 hour before the administration of capsaicin solution into the paw of the animals. The control group of animals was orally administered an equivalent volume of solvent - physiological sodium chloride solution (10 ml/kg).

It was established that GIZh-298, when administered orally once at doses of 40 and 60 mg/kg, exhibited an analgesic effect in the capsaicin test in mice, significantly reducing the duration of pain behavior in mice by 49.8% and 50.2% compared to the control group (Table 2).

Example 3

In tissue damage and inflammation, the formation of inflammatory mediators increases in the tissues, which sensitize primary afferent nociceptors [Coutaux A., Adam F., Wilier J.-C, Le Bars D. Joint Bone Spine. 2005; 72(5): 359-71; Ferreira S.H., Nakamura M., de Abreu Castro M.S. Prostaglandins. 1978; 16(1): 31-7; Khasar S.G., McCarter G., Levine J.D. J. Neurophysiol. 1999; 81(3): 1104-12], as a result of which pain sensitivity increases, i.e. hyperalgesia develops. Carrageenan is used to model inflammation-induced hyperalgesia by injecting it into the hind paw of rats and mice [Voronina T.A., Guzevatykh L.S. 2012]. In response to the injection of carrageenan solution, the level of bradykinin in the tissues increases, which leads to an increase in the concentration of TNF-α, cytokine-induced neutrophil chemoattractant (CINC)-1/CXCL1 and IL-1β, which in turn causes the release of prostaglandins and sympathetic amines [Cunha F.Q., Poole S., Lorenzetti B.B., Ferreira S.H. Brit. J. Pharmacol. 1992; 107(3): 660-4; 110(3): 1227-31], sensitizing primary afferent nociceptors [Coutaux A. et al. 2005; Ferreira S.H. et al. 1978; Khasar S.G. et al. 1999]. Three hours after the introduction of carrageenan into the hind paw of animals, a peak in the accumulation of neutrophils, which are involved in the formation of mechanical hypernociception, is observed in the tissues of its sole, determined by the activity of myeloperoxidase [Cunha T.M., Verri W.A., Schivo I.R., et al. J. Leukocyte Biol. 2008; 83(4): 824-32].

The experiment was performed on white male ICR mice weighing 24-26 g from the nursery of the Stolbovaya branch of the Federal State Budgetary Scientific Institution “Scientific Center for Biomedical Technologies of the Federal Medical and Biological Agency of Russia”. The work was organized and carried out in accordance with GOST 33216-2014 “Guidelines for the Maintenance and Care of Laboratory Animals. Rules for the Maintenance and Care of Laboratory Rodents and Rabbits”, GOST 33215-2014 “Guidelines for the Maintenance and Care of Laboratory Animals.

Hyperalgesia in carrageenan-induced inflammation in mice was assessed in two experiments. In the first, 50 μl of 2.5% carrageenan solution was used, which induces severe exudative inflammation of the paw in mice, and the studied compound GIZh-298 was administered orally one hour before the administration of the inflammation inducer. The administration of 50 μl of 2.5% carrageenan solution is used to model paw edema in order to assess the antiexudative effect of the compounds [Rafiee L., Hajhashemi V., Javanmard SH Cent. Eur. J. Immunol. 2019; 44(1): 15-22]. In the second experiment, a 1% carrageenan solution in a volume of 20 μl was used, and the studied compound GIZh-298 was administered orally 2 hours after the administration of the carrageenan solution [Voronina T.A., Guzevatykh L.S. 2012]. The severity of hyperalgesia was judged by a decrease in the sensitivity threshold to a mechanical stimulus in the von Frey test (a set of monofilaments with a nominal force of 0.008 to 300 g, Aesthesio ^® Von Frey Kit, Touch Test Sensory Evaluator, «Ugo Basile», Italy) 3 hours after the administration of the carrageenan solution. The von Frey threads were presented perpendicularly in different places on the plantar surface of the hind paws of the animals, excluding the areas of the toes and hock joint. For each von Frey thread, testing was performed 5 times with an interval of 3 seconds. The reaction threshold causing paw withdrawal was determined.

It was found that the introduction of a 2.5% carrageenan solution into the hind paw of mice leads to pronounced hyperalgesia: the sensitivity threshold of animals to a mechanical stimulus in the von Frey test decreased by 7.1 times (Table 3). GIZh-298, when administered orally once at doses of 40 and 60 mg/kg, significantly reduced the severity of hyperalgesia in mice and increased the sensitivity threshold of mice to a mechanical stimulus by 2.9 and 2.1 times, respectively, compared to animals that were orally administered the solvent (Table 3).

The introduction of a 1% carrageenan solution in a volume of 20 μl into the hind paw of mice caused hyperalgesia, characterized by a 6-fold decrease in the pain threshold in the von Frey test. GIZh-298, when administered orally once at doses of 10 and 20 mg/kg 2 hours after the introduction of the carrageenan solution into the paw of mice, significantly increased the sensitivity threshold of mice to a mechanical stimulus by 3.7 and 1.7 times, respectively (Table 4).

GIZh-298, when administered orally once at doses of 10 and 20 mg/kg 2 hours after the introduction of the carrageenan solution into the paw of mice, significantly increased the sensitivity threshold of mice to a mechanical stimulus by 3.7 and 1.7 times, respectively (Table 4).

Example 4

Visceral pain response in mice was modeled using the “Vinegar Writhing” method. Intraperitoneal administration of substances that irritate serous membranes, in particular acetic acid, causes contraction of the abdominal muscles, which in mice and rats is manifested by specific movements – writhing [Voronina T.A., Guzevatykh L.S., 2012].

The experiment was performed on white male ICR mice weighing 24-26 g from the nursery of the Stolbovaya branch of the Federal State Budgetary Scientific Institution “Scientific Center for Biomedical Technologies of the Federal Medical and Biological Agency of Russia”. The work was organized and carried out in accordance with GOST 33216-2014 “Guidelines for the Maintenance and Care of Laboratory Animals. Rules for the Maintenance and Care of Laboratory Rodents and Rabbits”, GOST 33215-2014 “Guidelines for the Maintenance and Care of Laboratory Animals.

Vinegar writhing test. Writhing was induced in animals by intraperitoneal administration of 0.9% acetic acid solution (10 ml/kg). After administration of acetic acid, the mice were individually placed in separate transparent plastic chambers for observation for 15 minutes, during which the number of writhings was recorded for each animal, starting from the moment of administration of acetic acid. Writhings are defined as contraction of the abdominal muscles combined with extension of the hind limbs [Voronina T.A., Guzevatykh L.S. 2012]. GIZH-298 was administered orally once at a dose of 60 mg/kg 1 hour before intraperitoneal administration of acetic acid solution. The control group of animals was orally administered an equivalent volume of solvent - physiological sodium chloride solution (10 ml/kg).

It was established that GIZh-298, when administered orally once at a dose of 60 mg/kg, significantly reduced the severity of visceral pain caused by intraperitoneal administration of 0.9% acetic acid in mice by 31.4% (Table 5).

Example 5

The spinal flexor reflex is a protective reflex used to assess pain sensitivity in experiments and clinical practice. The tail-flick test in mice is based on the spinal flexor reflex in response to progressively increasing exposure to thermal radiation on the skin surface. In this test, thermoreceptors, C-fibers of polymodal nociceptors, Ad-fibers of polymodal nociceptors, and high-threshold mechanoreceptors are sequentially activated [Voronina T.A., Guzevatykh L.S., 2012].

The experiment was performed on white male ICR mice weighing 24-26 g from the nursery of the Stolbovaya branch of the Federal State Budgetary Scientific Institution “Scientific Center for Biomedical Technologies of the Federal Medical and Biological Agency of Russia”. The work was organized and carried out in accordance with GOST 33216-2014 “Guidelines for the Maintenance and Care of Laboratory Animals. Rules for the Maintenance and Care of Laboratory Rodents and Rabbits”, GOST 33215-2014 “Guidelines for the Maintenance and Care of Laboratory Animals.

Tail flick test. Pain stimulation was applied locally to the tail by thermal radiation using a TSE-system analgesimeter (Germany). The intensity of the stimulation corresponded to a temperature increase from 46°C to 60°C for 15 seconds. The latent period (LP) of 15 seconds was considered the maximum permissible time for applying the stimulus. GIZh-298 was administered orally once at a dose of 60 mg/kg 1 hour before testing. The control group of animals was orally administered an equivalent volume of solvent - physiological sodium chloride solution (10 ml/kg).

In the tail flick test in mice, it was found that GIZh-298, when administered orally once at a dose of 60 mg/kg, affects the spinal flexor reflex and significantly increases the tail flick latency by 17.8% compared to the control group (Table 6).

Thus, GIZh-298 (4-benzoylpyridine oxalate (Z)-O-(2-morpholinoethyl)oxime) exerts analgesic effect in models of somatic and visceral pain after a single oral administration and has the ability to suppress the spinal flexor reflex in mice.

Claims (1)

The use of 4-benzoylpyridine oxalate (Z)-O-(2-morpholinoethyl)oxime (GIZH-298) as an analgesic.