Central nervous system effects of buspirone compared to diazepam in healthy volunteers and anxiety patients

Abstract

The central nervous system (CNS) effects of buspirone were evaluated in two separate double-blind, cross-over, placebo-controlled, quantitative pharmaco-EEG (QPEEG) studies. Single doses were used in healthy volunteers, and both single and multiple doses were evaluated in patients with generalized anxiety disorders (GAD). In healthy volunteers, statistically significant discrimination of CNS effects from placebo was observed even with the lowest single dose of buspirone (5 mg). In GAD patients, discrimination was observed only at the 10 mg buspirone level. Buspirone, in single or lower doses, produces CNS depressant effects. However, GAD patients who received 10 mg buspirone in single or multiple doses, exhibited CNS effects similar to diazepam and benzodiazepine anxiolytics. In addition, at both dose levels, and in at least one time period, buspirone also induced CNS effects similar to those of antidepressant drugs. This study indicates that although buspirone is different chemically and pharmacologically from diazepam and other benzodiazepine anxiolytics, at high and multiple doses it induces CNS effects similar to 'classic' anxiolytics in anxiety patients. Similar electrophysiological findings which correspond with similar clinical-therapeutic effects of buspirone and diazepam cannot be explained with the receptor binding. The discovery of the biochemical process which is responsible for producing 'anxiolytic' type CEEG alterations may be helpful in understanding the pathophysiology of anxiety disorder and its treatment.