Pharmacological and clinical effects of buspirone.

Clinical trials have demonstrated that buspirone (BuSpar) is effective in the treatment of anxiety with efficacy and dosage comparable to diazepam or chlorazepate. Buspirone has a unique structure and a pharmacologic profile which distinguishes it from the benzodiazepines. Because it lacks the anticonvulsant, sedative, and muscle-relaxant properties associated with other anxiolytics, buspirone has been termed "anxioselective." Animal studies suggest that it lacks potential for abuse, and this finding is supported by clinical investigations. Further preclinical work supports the contention that buspirone lacks liability to produce physical dependence or to significantly interact with central nervous system depressants such as ethanol. Moreover, biochemical investigations have not identified any direct interaction of buspirone with the benzodiazepine-gamma-aminobutyric acid-chloride ionophore complex. Pharmacologic studies on the molecular level indicate that buspirone interacts with dopamine and serotonin receptors. Recent behavioral, electrophysiological, and biochemical studies have clearly demonstrated that early hypotheses that buspirone might be considered a neuroleptic are no longer tenable. Recent evidence indicates that other neurotransmitter systems (serotonin, norepinephrine, acetylcholine) mediate buspirone's effects. It is hoped that future studies can define the mechanism by which buspirone alleviates the clinical manifestations of anxiety.