An anxiolytic agent and a serotonin receptor agonist belonging to the azaspirodecanedione class of compounds. Its structure is unrelated to those of the benzodiazepines, but it has an efficacy comparable to diazepam.
Buspar is used in the treatment of generalized anxiety where it has advantages over other antianxiety drugs because it does not cause sedation (drowsiness) and does not cause tolerance or physical dependence. Buspar differs from typical benzodiazepine anxiolytics in that it does not exert anticonvulsant or muscle relaxant effects. It also lacks the prominent sedative effect that is associated with more typical anxiolytics. in vitro preclinical studies have shown that buspar has a high affinity for serotonin (5-HT1A) receptors. Buspar has no significant affinity for benzodiazepine receptors and does not affect GABA binding in vitro or in vivo when tested in preclinical models. Buspar has moderate affinity for brain D2-dopamine receptors. Some studies do suggest that buspar may have indirect effects on other neurotransmitter systems.
Oral, rat LD50 = 136 mg/kg. Symptoms of overdose include dizziness, drowsiness, nausea or vomiting, severe stomach upset, and unusually small pupils.