A Controlled Double Blind Clinical Trial of Buspirone and Diazepam in Generalised Anxiety Disorder

Buspirone hydrochloride is a now nonbenzodiazepine, non-barbiturate, non-narcotic t ranquil izer . It is an 'agaspirodecanedione", lipophilic and a heterocyclic compound. Absorption of buspironc from gastrointestinal tract is virtually complete. Peak plasma level is achieved in less, than one hour after a single dose. T h e elimination half life of the drug ranges from 2 to 8 hours in healthy subjects and is significantly lengthened in renal and hepatic disease. Although mechanism of the anxiolytic effect of buspirone is undetermined, complex interactions with several central nervous system neurotransmitters, especially serotonin are thought to be contributory. Unlike benzodiazepine buspirone lacks hypnotic, anticonvulsant and muscle relaxant properties and has been termed anxio-selective (Eison and Temple, 1986; Skolnick et al., 1985). In a few double blind clinical trials, buspirone in 15-30 mg/day doses, improved symptoms of anxiety, assessed by standard rating scales, similar to diazepam and clorazepate (Cohn et al . , 1986; Feighner et al., 1982; Goldberg and Finnerty, 1979, 1982). Like diazepam, buspirone is effective in patients with mixed anxiety-depression (Feighner et al. , 1982; Cohn et al., 1986). In healthy volunteers buspirone does not impair psychomotor or cognitive function (Smiley and Moskowitz, 1986). Because of its lack of euphoric effect, buspirone appears unlikely to become a drug of abuse (Cole ct al., 1982, Griffith et al., 1986).