AGENTS FOR TREATING SUBSTANCE ABUSE DISORDERS

Abstract: A method for relief or prevention of a withdrawal syndrome resulting from addiction to a drug or substance of abuse and/or for the suppression of dependence on drugs or substances of abuse which comprises administering an effective amount of bisphenylalkylpiperazines of formula (I) and the pharmaceutically acceptable acid addition salts thereof.

Description: AGENTS FOR TREATING SUBSTANCE ABUSE DISORDERS FIELD OF THE INVENTION The present invention relates to a new use of certain pyridyl- and pyrimidyl-substituted bisphenylalkylpiperazine in the treatment of substance abuse disorders . More partic larly, this invention relates to the amelioration of with¬ drawal symptoms and to modify drug-seeking behaviour. BACKGROUND OF THE INVENTION Drug dependency is extremely difficult to escape. This is true whether the dependency is one based on ethanol, amphetamine, barbiturates, benzodiazepines, cocaine, nicoti opioids, and phencyclidine or the like. There is a need, therefore for an agent decreasing or overcoming such addict and, if possible reducing or eliminating the symptoms relat to the withdrawal of such drugs or substances of abuse. Different classes of neuronal receptors and neurotrans- itters in the brain have been implicated in the complex mechanisms underlying for example the compulsive drinking o alcohol. Experimental findings have f voured the opioid, dopaminergic, serotonergic, and benzodiazepine receptor subtypes . Based upon a large number of genetic and pharmacologica studies, serotonin (5-HT) containing neurons in the limbic- midbrain and limbic-forebrain pathways are seemingly involv in part, in the fundamental mechanisms underlying for examp alcohol drinking. A number of reports have established that 5-HT uptake blockers significantly attenuate ethanol intake in rats. F example, zimelidine (The Merck Index 11th Ed., No. 10024) w found to have a potent inhibitory effect on voluntary ethan consumption in rats. In human trials, zimelidine was shown increase the number of abstinent days and to produce a slig reduction in the number of daily drinks . There is ample ev dence that serotonin is involved in the regulation of both food and fluid intake. Zimelidine was found to attenuate the ingestion of food and alcohol concomitantly. It is possible, therefore, that zimelidine' ' s action is mediated through more global effects on cσnsummatory behaviour rather than specific effects on ethanol reinforcement. Buspirone (The Merck Index 11th Ed., No. 1493), a partial 5-HT 1A agonist, has been found to be effective for the treat¬ ment of anxiety. Buspirone was reported to attenuate signifi cantly the consumption of alcohol by monkeys. In a clinical trial comparing buspirone to placebo in alcohol-dependent individuals, there was a lower drop-out rate in the buspirone treated group, which also reported fewer signs of craving. A perozide (The Merck Index 11th Ed., No. 612), a 5-HT 2 antagonist, was reported to significantly attenuate the intak of alcohol in rats without affecting neither consumption of food nor level of body weight. SUMMARY OF THE INVENTION I has now surprisingly been found that bisphenylalkyl¬ piperazines of formula and the pharmaceutically acceptable acid addition salts thereof, wherein R χ and ' R- are the same or different and selected fro hydrogen or halogen; R. J and R 4 are the same or different and selected from hydrog or alkyl having 1 to 5 carbon atoms; n is 2 or 3; A is selected from the following pyrimidyl- or pyridyl-grou wherein R 5 is selected from hydrogen, alkyl having 1 to 5 carbon atoms or halogen; R 6 and R-. are the same or different and selected from hydrogen, halogen, alkyl having 1 to 5 carbon atoms, alkoxy having 1 to 5 carbon atoms, hydroxy, cyano, nitro, trifluoromethyl, COOR e , CONR g R 10 or COB; wher R 8 is hydrogen or alkyl having 1 to 5 carbon atoms; R g and are the same or different and selected from hydrogen, alkyl having 1 to 5 carbon atoms or cycloalkyl having 3 to 8 carb atoms; B is selected from wherein m is 1, 2, 3, or 4; R. 1 is selected from hydrogen o alkyl having from 1 to 5 carbon atoms; and when used in the foregoing definitions the term alk is meant to include straight and branched hydrocarbon groups the term alkoxy is meant to include straight and branched alkoxy groups; the term halogen is meant to include fluoro, chloro and bromo, are unexpectedly effective and specific in the treatmen of individuals addicted to drugs or substances of abuse, suffering from symptoms related to withdrawal of such drugs substances. This finding opens up a new method of treating dependence on drugs, such as alcohol, hallucinogens, minor tranquilizers, nicotine, opiates, and stimulants. The aforementioned term "pharmaceutically acceptable aci addition salt" is meant to comprise these salts obtained by treating the base form of the active ingredients of formula (I) with appropriate acids, such as, for example, inorganic acids, e.g. hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, and phosphoric acid, or organic acids, e. acetic acid, propanoic acid, glygolic acid, lactic acid, malonic acid, succinic acid, fumaric acid, tartaric acid, citric acid, and pamoic acid. Conversely, the salt form can be converted into the free base form by treatment with alkali The compounds of formula (I) as well as their preparation and pharmacological properties are known from U.S. Pat. No . 4, 937,245. DETAI.LED DESCRIPTION OF THE INVENTION Twenty years of research has consistently demonstrated that drugs or substances that are abused by man are usually self-administered by laboratory animals. Ethanol, amphet¬ amine, barbiturates, benzodiazepines, cocaine, nicotine, opioids, and phencyclidine and the like are just a few examples of substances abused by man and self-administered in animal models. The value of animal models for investigating the pharmacological and behavioural mechanisms underlying dru dependence has been repeatedly demonstrated. In fact, the animal models are our only recourse for the investigation of compounds to ameliorate or modify drug-seeking behaviour. In relation to this there is considerable experimental evidence supporting that a commonalty in the mechanism of the addictiv process itself exists in the brain stem which underlies the predilection to abuse the above mentioned drugs. The present invention relates to a method for treating substance abuse disorders by administering to a patient suf¬ fering from abuse a therapeutically effective amount of a compound of formula (I) or a pharmaceutically acceptable aci addition salt thereof. Specifically the invention relates to the relief or prevention of a withdrawal syndrome resulting from addiction to a drug or substance of abuse and/or for th suppression of dependence on drugs or substances of abuse. Repeated administration to a subject of certain drugs su as alcohol, hallucinogens, minor tranquilizers, nicotine, opiates, and stimulants can lead to physical and/or psycho¬ logical dependence upon that drug or substance. When the dr or substance of abuse is withdrawn from a dependent subject, the subject develops certain symptoms including sleep and mo disturbance and intense craving for the drug or substance of abuse. These symptoms may be collectively described as a withdrawal syndrome in connection with the present invention Although drug treatments for substance abuse disorders a available, these remain largely ineffective and unspecific and, therefore, improvement is needed. The anorexic and oth effects of for example 5-HT reuptake. blockers and buspirone constitute a major impediment to their consideration for cli nical treatment. . The compounds of formula (I) have been fou to be both chemically and pharmacologically different from those drugs, suggested hitherto for the treatment of drug dependence. A preferred compound is FG5893 (2- [4- [4, -bis (4 -fluorophenyl)butyl] -1-piperazinyl] -3-pyridinecarbox lic aci methyl ester dihydrochloride ethylat) . FG5893 represents a new and novel class of psychotropic agents by having high affinity for both 5-HT 1A and 5-HT 2 receptors in combination with potent 5-HT reuptake inhibiting properties. The following example is intended to illustrate the present invention without limiting the scope thereof: 2- [4- [4,4-bis (4-fluorophenyl)butyl] -1-piperazinyl] - -3-pyridinecarboxylic acid methyl ester 20 g (0.061 mole) of 1- [4,4-bis (p-fluorophenyl)butyl] - -piperazine, 10 g (0.058 mole) of 2-chloro-3-pyridinecarboxy acid methyl ester and 10 g (0.07 mole) of potassium carbonat were heated and stirred with 20 ml of toluene at 120°C (tem¬ perature of oil bath) for 20 h. After cooling, 40 ml of toluene was added. The mixture filtered. The toluene solution was extracted with H_0. The organic phase was dried over anhydrous Na 2 S0 4 and evaporated yield 15 g (55%) of the free base of the title compound. The crude base was dissolved in ethanol and excess HCl in ethanol was added. Ether was added to precipitate 2- [4- [4,4-bis (4- -fluorophenyl)butyl] -1-piperazinyl] -3-pyridinecarboxylic aci methyl ester dihydrochloride ethylat, m.p. 153-66°C (sintere The dihydrochloride salt was dissolved in hot H 2 0. The solution was cooled to precipitate the hydrochloride salt. Recrystallization from aceton/ether yielded 2- [4- [4,4-bis (4- - luorophenyl)butyl]-1-piperazinyl] -3-pyridinecarboxylic aci methyl ester hydrochloride, m.p. 167-68°C. Table 1. Dru affinit or serotoner ic rece tor subt es. a) Radioligand: 3 H-8-0H-DPAT Tissue: Hippocampus b) 3 H-Ketanserin Cerebral cor Table 2. Inhibition of reuptake of [ 3 H-5-HT] by synaptosome from rat frontal cortex. Compound IC 50 (μM) FG5893 0.08 Zimelidine 0.12 Buspirone 22 Amperozide 0.32 According to the method of Shank, R.P. et al. Λ J. Pharmacol. Exp. Ther. 242:74-84, 1987. To further illustrate the useful pharmacological proper of FG5893, the effect of FG5893 administered systemically w determined in Sprague-Dawley rats induced to drink alcohol chronically by a series of intraperitoneal injections of cy amide according to experimental procedures described previo (Critcher, E.C. and R.D. Myers, Alcohol 4:347-353, 1987) . takes of food and body weights were recorded. FG5893 in a dose of 0.5, 1.0 and 2.5 mg/kg was administ twice a day for three consecutive days. Whereas control i tions of saline were without effect on alcohol consumption, doses of FG5893 significantly reduced the intake of alcohol terms of both absolute g/kg and proportion of alcohol to to fluid intake. Further, the 1.0 and 2.5. g/kg doses of FG58 continued to suppress alcohol consumption over two 4-day te immediately following the injection sequence and after a 40 interval. Neither body weights nor intakes of food of the were affected by FG58 3 either during or after its administ tion, suggesting a pharmacological specificity of action of this compound. This finding is notable because drugs that attenuate the preference for alcohol consumed in a concentr tion of pharmacological consequence typically impair the in tion of food. The compounds of formula (I) and their acid addition sa are therefore indicated for use in amelioration of withdraw symptoms and in modifying drug-seeking behaviour. Effective quantities of the compounds of formula (I) an their acid addition salts are preferably administered to a patient in need of such treatment according to usual routes administration and formulated in usual pharmaceutical co po tions comprising an effective amount of the active ingredie and a suitable pharmaceutically acceptable carrier. Such c positions may take a variety of forms, e.g. solutions, susp sions, emulsions, tablets, capsules, and powders prepared f oral administration, patches for transder al administration sterile solutions for parenteral administration. A suitable daily dose for use in the treatment of substan abuse disorders is contemplated to vary between 0.01 mg/kg to -* " about 10 mg/kg body weight, in particular between 0.01 mg/kg 1 mg/kg body weight, depending upon the specific condition to be treated, the age and weight of the specific patient, and t specific patient's response to the medication. The exact in vidual dosage, as well as the daily dosage, will be determine according to standard medical principles under the direction a physician. 0 Various additives to enhance the stability or ease of administration of the drug are contemplated. The pharmaceutic composition may also contain additional therapeutically usefu substances other than a compound of formula (I) .

Claims: We claim: 1. Use of a bisphenylalkylpiperazines of formula and the pharmaceutically acceptable acid addition salts thereof, wherein R χ and R 2 are the same or different and selecte from hydrogen or halogen; R 3 and R 4 are the same or different and selected from hydrogen or alkyl having 1 to 5 carbon atoms; n is 2 or 3; A is selected from the following pyrimidyl- or pyridyl- groups: wherein R 5 is selected from hydrogen, alkyl having 1 to carbon atoms or halogen; R 6 and R-, are the same or diff ent and selected from hydrogen, halogen, alkyl having 1 5 carbon atoms, alkoxy having 1 to 5 carbon atoms, hydroxy, cyano, nitro, trifluoromethyl, COOR g , CONR 9 R 10 COB; wherein R 8 is hydrogen or alkyl having 1 to 5 carb atoms; R g and R 10 are the same or different and selecte from hydrogen, alkyl having 1 to 5 carbon atoms or cycloalkyl having 3 to 8 carbon atoms; B is selected from wherein m is 1, 2, 3, or 4; R lχ is selected from hydrogen or alkyl having from 1 to 5 carbon atoms; and when used in the foregoing definitions the term alkyl is meant to include straight an branched hydrocarbon groups; the term alkoxy is meant to include straight and branched alkoxy groups; the term halogen is meant to include fluoro, chloro and bromo, for the manufacture of a medicament for the relief or prevention of a withdrawal syndrome resulting from addic- tion to a drug or substance of abuse and/or for the sup¬ pression of dependence on drugs or substances of abuse. 2. A method for relief or prevention of a withdrawal syndrom resulting from addiction to a drug or -substance of abuse and/or for the suppression of dependence on drugs or substances of abuse which comprises administering an effective amount of a bisphenylalkylpiperazines of formul and the pharmaceutically acceptable acid addition salts thereof, wherein R χ and R 2 are the same or different and selected from hydrogen or halogen; R 3 and R 4 are the same or different and selected from hydrogen or * aϋkyl having 1 to 5 carbon atoms; n is 2 or 3; A is selected from the following pyrimidyl- or pyridyl- groups: wherein 5 is selected from hydrogen, alkyl having 1 to carbon atoms or halogen; R g and R 7 are the same or diff ent and selected from hydrogen, halogen, alkyl having 1 5 carbon atoms, alkoxy having 1 to 5 carbon atoms, hydroxy, cyano, nitro, trifluoromethyl, COOR 8 , CONR g R 10 COB; wherein R 8 is hydrogen or alkyl having 1 to 5 carb atoms; R 9 and R 10 are the same or different and selecte from hydrogen, alkyl having 1 to 5 carbon atoms or cycl alkyl having 3 to 8 carbon atoms; B is selected from wherein m is 1, 2, 3, or 4; R χχ is selected from hydrog or alkyl having from 1 to 5 carbon atoms; and when used in the foregoing definitions the term alk is meant to include straight and branched hydrocarbon groups; the term alkoxy is meant to include straight an branched alkoxy groups; the term halogen is meant to include fluoro, chloro and bromo. The use of Claim 1, wherein R χ is hydrogen and R 2 is fluoro, wherein R 3 and R 4 are hydrogen, wherein n is 2, wherein A is wherein R 6 is hydrogen and R at the 3-pcώition is COOR and wherein R 8 is methyl; or a pharmaceutically accepta salt thereof. . The method of Claim 2, wherein ^ is hydrogen and ^ is fluoro, wherein R 3 and R 4 are hydrogen, wherein n is 2, wherein A is wherein R 6 is hydrogen and R-. at the 3-position is C00R 8 , and wherein R 8 is methyl; or a pharmaceutically acceptabl salt thereof. •

Inventors: ANDERSSON GUNNAR, BJOERK ANDERS, ANDERSSON, GUNNAR, BJOERK, ANDERS
Applicants: ANDERSSON GUNNAR, BJOERK ANDERS, KABI PHARMACIA AB
Application year: 1993
Main classification: A61K31
IPC codes: A61K31, A61P25, A61P43, C07D211, C07D213, C07D239, C07D295, C07D401, C07D403