Buspirone. A preliminary review of its pharmacological properties and therapeutic efficacy as an anxiolytic.

Buspirone hydrochloride (HCl)1 is a new anxiolytic with a unique chemical structure. Its mechanism of action remains to be elucidated. Unlike the benzodiazepines, buspirone lacks hypnotic, anticonvulsant and muscle relaxant properties, and hence has been termed 'anxioselective'. As evidenced by a few double-blind clinical trials, buspirone 15 to 30 mg/day improves symptoms of anxiety assessed by standard rating scales similarly to diazepam, clorazepate, alprazolam and lorazepam. Like diazepam, buspirone is effective in patients with mixed anxiety/depression, although the number of patients studied to date is small. In several studies, a 'lagtime' of 1 to 2 weeks to the onset of anxiolytic effect has been noted; hence motivation of patient compliance may be necessary. Sedation occurs much less often after buspirone than after the benzodiazepines; other side effects are minor and infrequent. In healthy volunteers, buspirone does not impair psychomotor or cognitive function, and appears to have no additive effect with alcohol. Early evidence suggests that buspirone has limited potential for abuse and dependence. Thus, although only wider clinical use for longer periods of time will more clearly define some elements of its pharmacological profile, with its low incidence of sedation buspirone is a useful addition to the treatments available for generalised anxiety. It may well become the preferred therapy in patients in whom daytime alertness is particularly important.