it is to be understood that the invention extends to the use of each of the stereoisomeric forms of the compounds of the present invention as well as the pure diastereomeric , pure enantiomeric , and racemic forms of the named compounds . the term &# 34 ; low lipophilicity &# 34 ; refers to hydrogen , halogen , -- cf 3 , -- or 25 , -- nr 25 r 26 , -- nhor 25 , -- nhnh 2 , -- cn , cor 8 , or a substituted or unsubstituted , saturated or unsaturated hydrocarbon group ; wherein r 25 is hydrogen , c 1 - c 6 alkyl , c 2 - 6 alkenyl or c 2 - 6 alkynyl ; r 26 is hydrogen , alkyl or -- coch 3 , and r27 represents -- or 25 or -- nr 25 r 26 ; the term azacyclic or azabicyclic ring system is a non - aromatic ring system containing one nitrogen atom as the sole heteroatom . sutably , the ring system contains from 4 - 10 ring atoms , preferably from 5 - 8 ring atoms . preferably , the ring system contains a tertiary amino nitrogen atom in a caged structure . the bicyclic systems may be fused , spiro , or birdged . preferably , the nitrogen atom is at a bridgehead in a bicyclic system . examples of such heteroatoms include the heteroatoms described in u . s . pat . no . 5 , 260 , 293 , columns 2 - 3 , which has been incorporated by reference . the term &# 34 ;&# 39 ; 927 azacyclic or &# 39 ; 927 azabicyclic &# 34 ; refers to a non - aromatic ring system contianing one nitrogen atom as the sole heteroatom . suitably the ring contains from 4 to 10 ring atoms . preferably from 5 - 8 ring atoms . the bicyclic systems may be fused , spiro or bridged . examples of such heteroatoms include the bicyclic heteroatoms described in u . s . pat . no . 5 , 242 , 927 column 2 , which has been incorporated by reference . the most preferred &# 39 ; 927azabicyclic or &# 39 ; 927azacyclic systems include pyrrolidine , 1 , 2 , 5 , 6 - tetrahydropyridine , quinuclidine or 1 - azabicyclo [ 2 . 2 . 1 ] heptane ring , optionally substituted with methyl or hydroxy . an especially preferred &# 39 ; 927 azabicyclic ring is quinuclidine , which is substituted by hydrogen , methyl or hydroxy at any available atom . groups which are converted in vivo to an amino group on the compounds claimed herein for treating anxiety may be ascertained by administering the compound to a human or an animal and detecting , by conventional analytical techniques , the prescense of the corresponding compound having an amino substituent in the urine of a human or animal . examples of such groups include groups which are hydrolysable in vivo to an amino group , such as amido , urethan substituents . in particular a group of the formula -- nh . q wherein q represents cho , cor 33 or co 2 r 33 , and r 33 represents an optionally substituted hydrocarbon group . the term hydrocarbon group includes groups having up to 20 carbon atoms , suitably up to 10 , and conveniently up to 8 carbon atoms . suitable hydrocarbon groups include c 1 - 8 alkyl , c 2 - 8 alkenyl , c 2 - 8 alkynyl , c 3 - 7 cycloalkyl , c 3 - 7 cycloalkylc 1 - 6 alkyl , aryl and arylc 1 - 6 alkyl . suitable r 34 groups include the following : ## str38 ## wherein the broken line represents an otpional chemical bond ; and r 41 and r 42 may be present at any position , including the point of attachment to the benzene ring , and independently represent hydrogen , c 1 - 4 alkyl , f , br , cl , c 1 - 4 alkoxy , hydroxy , carboxy , or c 1 - 4 alkyoxycarbonyl or r 41 and r 42 together represent cabonyl . the nitrogen atom may be substituted by hydrogen or c 1 - 4 alkyl . the term &# 34 ; phenyl - c 1 - c 4 alkyl &# 34 ; designates an alkyl group which is substituted with a phenyl group . preferred phenyl - alkyl groups include benzyl , 1 - and 2 - phenylethyl , 1 -, 2 -, 3 - phenyla propyl and 1 - methyl - 1 - phenylethyl . the phenyl group may be optionally be substituted with from 1 - 3 independently selected named substituents . the term &# 34 ; form together with the nitrogen atom to which they are joined , a heterocyclic radical &# 34 ; means that a heterocyclic radical optionally containing another heteroatom , for example , s or o . such groups include , but are not limited to , piperidyl , piperazynyl , morpholinyl , and pyrrolidinyl . the term &# 34 ; alkyl &# 34 ; refers to the number of carbon atoms indicated ; however , when no number is specified , the term refers to c 1 - 6 alkyl . the alkyl may be linear or branched unless specified . the term &# 34 ; alkynyl &# 34 ; has its accepted meaning ; however , if the number of carbon atoms are unspecified , it refers to c 2 - 10 alkynyl . the alkynyl group may be linear or branched unless specified . the term &# 34 ; antianxiety dose &# 34 ;, as used herein , represents an amount of compound necessary to prevent or treat a human susceptible to or suffering from anxiety following administration to such human . the active compounds are effective over a wide dosage range . for example , dosages per day will normally fall within the range of about 0 . 005 to about 500 mg / kg of body weight . in the treatment of adult humans , the range of about 0 . 05 to about 100 mg / kg , in single or divided doses , is preferred . however , it will be understood that the amount of the compound actually administered will be determined by a physician , in the light of the relevant circumstances including the condition to be treated , the choice of compound to be administered , the age , weight , and response of the individual patient , the severity of the patient &# 39 ; s symptoms , and the chosen route of administration , and therefore the above dosage ranges are not intended to limit the scope of the invention in any way . while the present compounds are preferably administered orally to humans susceptible to or suffering from anxiety , the compounds may also be administered by a variety of other routes such as the transdermal , parenterally , subcutaneous , intranasal , intramuscular and intravenous routes . such formulations may be designed to provide delayed or controlled release using formulation techniques which are known in the art . as used herein the term &# 34 ; treating &# 34 ; includes prophylaxis of a physical and / or mental condition or amelioration or elimination of the developed physical and / or mental condition once it has been established or alleviation of the characteristic symptoms of such condition . as used herein the term &# 34 ; anxiety &# 34 ; refers to an anxiety disorder . examples of anxiety disorders which may preferredly be treated using an effective amount of a named compound or pharmaceutically acceptable salt thereof include , but are not limited to : panic attack ; agoraphobia ; acute stress disorder ; specific phobia ; panic disorder ; psychoactive substance anxiety disorder ; organic anxiety disorder ; obsessive - compulsive anxiety disorder ; posttraumatic stress disorder ; generalized anxiety disorder ; and anxiety disorder nos . examples of anxiety disorders which may more preferredly be treated using an effective amount of a named compound or a pharmaceutically acceptable salt thereof include panic attack ; panic disorder ; psychoactive substance anxiety disorder ; organic anxiety disorder ; obsessive - compulsive anxiety disorder ; posttraumatic stress disorder ; generalized anxiety disorder ; and anxiety disorder nos . examples of the anxiety disorders which are most preferredly treated using a named compound include organic anxiety disorder ; obsessive - compulsive disorder ; posttraumatic stress disorder ; generalized anxiety disorder ; and anxiety disorder nos . the named anxiety disorders have been characterized in the dsm - iv - r . diagnostic and statistical manual of mental disorders , revised , 4th ed . ( 1994 ). the dsm - iv - r was prepared by the task force on nomenclature and statistics of the american psychiatric association , and provides clear descriptions of diagnostic catagories . the skilled artisan will recognize that there are alternative nomenclatures , nosologies , and classification systems for pathologic psychological conditions and that these systems evolve with medical scientific progress . the compounds employed in the invention are not believed to act via the gaba / benzodiazepine , 5ht1a , or d1 receptor systems in humans . rather , the activity of the present compounds as antianxiety agents is believed to be based upon modulation of muscarinic cholinergic receptors . however , the mechanism by which the present compounds function is not necessarily the mechanism stated supra ., and the present invention is not limited by any mode of operation . the following examples are studies to establish the usefulness of the named compounds for treating anxiety . the antianxiety activity of the compounds employed in the method of the present invention is established by demonstrating that the compounds increase punished responding . this procedure has been used to establish antianxiety activity in clinically established compounds . according to this procedure , the responding of rats or pigeons is maintained by a multiple schedule of food presentation . in one component of the schedule , responding produces food pellet presentation only . in a second component , responding produces both food pellet presentation and is also punished by presentation of a brief electric shock . each component of the multiple schedule is approximately 4 minutes in duration , and the shock duration is approximately 0 . 3 seconds . the shock intensity is adjusted for each individual animal so that the rate of punished responding is approximately 15 to 30 % of the rate in the unpunished component of the multiple schedule . sessions are conducted each weekday and are approximately 60 min in duration . vehicle or a dose of compound are administered 30 min to 6 hr before the start of the test session by the subcutaneous or oral route . compound effects for each dose for each animal are calculated as a percent of the vehicle control data for that animal . the data are expressed as the mean ± the standard error of the mean . further , the antianxiety activity of the compounds is established by demonstrating that the compounds are effective in the monkey taming model . plotnikoff res . comm . chem . path . & amp ; pharmacol ., 5 : 128 - 134 ( 1973 ) described the response of rhesus monkeys to pole prodding as a method of evaluating the antiaggressive activity of a test compound . in this method , the antiaggressive activity of a compound was considered to be indicative of its antianxiety activity . hypoactivity and ataxia were considered to be indicative of a sedative component of the compound . the present study is designed to measure the pole prod response - inhibition induced by a compound of this invention in comparison with that of a standard antianxiety compound such as diazepam as a measure of antiaggressive potential , and to obtain an indication of the duration of action of the compound . male and female rhesus or cynomologous monkeys , selected for their aggressiveness toward a pole , are housed individually in a primate colony room . compounds or appropriate vehicle are administered orally or subcutaneously and the animals are observed by a trained observer at varying times after drug administration . a minimum of three days ( usually a week or more ) elapses between treatments . treatments are assigned in random fashion except that no monkey receives the same compound two times consecutively . aggressiveness and motor impairment are graded by response to a pole being introduced into the cage as described in table 1 . the individuals responsible for grading the responses are unaware of the dose levels received by the monkeys . table 1______________________________________grading of monkey response to pole introductionresponse grade description______________________________________attack 2 monkey immediately grabbed and / or bit pole as it was placed at opening in cage . 1 monkey grabbed and / or bit pole only after the tip was extended into the cage 12 inches or more . 0 no grabbing or biting observed . pole push 2 monkey grabbed the pole to attack it or push it away . 1 monkey touched the pole only in attempting to avoid it or rode on the pole ( avoidance ). 0 no pushing , grabbing or riding of the pole observed . biting 2 monkey bit aggressively and frequently . 1 monkey bit weakly or infrequently 0 no biting observed . ataxia 2 monkey exhibited a marked loss of coordination . 1 slight loss of coordination observed . 0 no effects on coordination observed . hypoactivity 2 marked : monkey was observed in a prone position . may or may not have responded by rising and moving away when experimenter approached . 1 slight : monkey did not retreat as readily when experimenter approached 0 none . antiaggression + dose of drug was active in decreasingactivity of global assessment of aggressive behaviordrug dose - dose of drug was not active in decreasing aggressive behavior______________________________________ finally , the antianxiety activity of the named compounds can be demonstrated by human clinical trials . the study was designed as a double - blind , parallel , placebo - controlled multicenter trial . the patients were randomized into four groups , placebo and 25 , 50 , and 75 mg tid of test compound . the dosages were administered orally with food . patients were observed at four visits to provide baseline measurements . visits 5 - 33 served as the treatment phase for the study . during the visits , patients and their caregivers were questioned and observed for signs of agitation , mood swings , vocal outbursts , suspiciousness , and fearfulness . each of these behaviors are indicative of the effect of the test compound on an anxiety disorder . ______________________________________ placebo 25 mg 50 mg 75 mgbehavioral ( n = 87 ) ( n = 85 ) ( n = 83 ) ( n = 87 ) event p n (%) n (%) n (%) n (%) ______________________________________agitation . 006 40 ( 46 ) 34 ( 40 ) 24 ( 29 ) 20 ( 23 ) mood swings . 025 40 ( 46 ) 25 ( 29 ) 21 ( 25 ) 28 ( 32 ) vocal . 001 33 ( 38 ) 29 ( 34 ) 24 ( 29 ) 11 ( 13 ) outburstssuspiciousness . 001 32 ( 37 ) 23 ( 27 ) 26 ( 31 ) 7 ( 8 ) fearfulness . 038 25 ( 29 ) 28 ( 33 ) 19 ( 23 ) 13 ( 15 ) ______________________________________ treatment groups were compared with respect to the number and percent of patients who ever had the symptom during the double - blind portion of the study ( visits 5 through 33 ), at a severity that was worse than during the baseline visits ( 1 through 4 ). ( 3r , 4r )- 3 -( 3 - cyclopropyl - 1 , 2 , 4 - oxadiazol - 5 - yl )- 1 - azabicyclo [ 2 . 2 . 1heptane and compounds of formulae iv , v , viii , ix , xiii , xiv , and xv ; or especially preferred compounds include the following : compounds of formulae xiii , xiv , and xv . examples of preferred compounds include , but are not limited to , 3 -[ 2 -( 6 - hydroxypyrazin ) yl ]- 1 - azabicyclo [ 2 . 2 . 2 ] octane , 3 -( 2 - pyrazinyl )- 1 - azabicyclo [ 2 . 2 . 1 ] heptane , 6 -( 2 - pyrazinyl )- 1 - azabicyclo [ 3 . 2 . 1 ] octane , 6 -( 2 - pyrazinyl )- 1 - azabicyclo [ 3 . 2 . 1 ] octan - 6 - ol , 3 - fluoro - 3 -( 2 - pyrazinyl )- 1 - azabicyclo [ 2 . 2 . 1 ] heptane , 1 - methyl - 3 -( 2 - pyrazinyl ) pyrrolidine , 3 -[ 2 -( 3 - methylpyrazin ) yl ]- 1 - azabicyclo [ 2 . 2 . 2 ] octan - 3 - ol , 3 -[ 2 -( 3 , 6 - dimethylpyrazin ) yl ]- 1 - azabicyclo [ 2 . 2 . 1 ] heptane , 3 -[ 2 -( 6 - allyloxypyrazin ) yl ]- 1 - azabicyclo [ 2 . 2 . 1 ] heptane , 3 -[ 2 -( 6 - methoxypyrazin ) yl ]- 1 - azabicyclo [ 2 . 2 . 2 ] octane , 3 -[ 2 -( 6 - chloropyrazin ) yl ]- 1 , 2 , 5 , 6 - tetrahydropyridine , 3 -[ 5 -( 3 - octanyloxycarbonylamino - 1 , 2 , 4 - oxadiazol )- yl ]- 1 - azabicyclo ] 2 . 2 . 1 ] heptane , 3 -[ 5 -( 3 - cyclohexylcarbonylamino - 1 , 2 , 3 - oxadiazol )- yl ] quinuclidine , 3 -[ 5 -( 3 -( 1 -( 3 - n - pentyloxycarbonyl )- 1 - ethoxycarbonylamino )- 1 , 2 , 4 - oxadiazol )- yl ] quinuclidine , 3 -[ 5 -( 3 - octanoylamino - 1 , 2 , 4 - oxadiazol )- yl ] quinuclidine , 3 -[( 1 - methyl - 1h - imidazol - 5 - yl ) methyl ] 1 , 2 , 4 - oxadiazol - 5 ( 4h - one , 4 - methyl - 3 -[( 1 - methyl - 1h - imidazol - 4 - yl )- methyl ] 1 , 2 , 4 - oxadiazol - 5 ( 4h )- one , 4 - ethyl - 3 [( 1 - methyl - 1h - imidazol - 4 - yl )- methyl ]- 1 , 2 , 4 - oxadiazol - 5 ( 4h )- one , n -[ 4 -( hexahydro - 1h - azaepin - 1 - yl )- 2 - butynyl ]- n , n - dimethyl urea , n -[ 4 - 1 - pyrrolidinyl )- 2 - butynyl ]- urea , 5 - acetyl - 1 - azabicyclo [ 3 . 1 . 1 ] heptane , 1 - azabicyclo [ 3 . 1 . 1 ] hept - 5 - ylcarboxaldehyde , 3 -( 2 - methyltetrazol - 5 - yl )- 1 - azabicyclo [ 2 . 2 . 1 ] heptane , 3 -( 2 - methyl - 1 , 2 , 3 - triazol - 4 - yl )- 1 - azabicyclo -[ 2 . 2 . 2 ] octane , 3 -( 3 - cyclopropyl - 1 , 2 , 4 - oxadiazol - 5 - yl )- 1 - azabicyclo [ 2 . 2 . 1 ] heptane , and a pharmaceutically acceptable salt or solvate thereof .
the present invention provides a method for treating anxiety in a human in need thereof , comprising administering an antianxiety amount of a muscarinic agonist compound of the general formula ## str1 ## wherein x r 43 , r 44 , r 45 and r 46 are defined in the disclosure .