19.03.6 Buspirone

Buspirone is a 5-HT_1A receptor partial agonist found to be somewhat useful in treatment of panic disorder and generalised anxiety disorder. 5-HT_1A receptor activation usually inhibits release of neurotransmitters like serotonin from the raphe nuclei and noradrenaline from the locus coeruleus. Buspirone therefore partially blocks noradrenaline release, hence centrally-mediated physiological arousal. By partially blocking somatic 5-HT_1A autoreceptors on raphe nuclei, buspirone also facilitates release of serotonin. The therapeutic effects, however, take days to weeks to occur, therefore must involve more complex mechanisms for anxiolytic action. Side effects of buspirone include dizziness, nausea, headache and restlessness, but it avoids the psychomotor impairment and dependence liability incurred with the use of benzodiazepines.