buspirone + fluoxetine

Buspirone + fluoxetine is a combination of two small molecule pharmaceuticals used off-label for the treatment of comorbid anxiety and depressive disorders. Buspirone is an anxiolytic that acts primarily as a partial agonist at serotonin 5-HT1A receptors, with additional weak antagonism at dopamine D2, D3, and D4 receptors and partial agonism at alpha-1 adrenergic receptors. Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) antidepressant that increases synaptic serotonin by inhibiting its reuptake in the central nervous system. The combination may be considered in patients with both depression and anxiety symptoms; however, co-administration increases the risk of serotonin syndrome due to additive serotonergic effects. Some studies suggest buspirone may potentiate certain neurochemical effects of fluoxetine but could delay onset of antidepressant efficacy compared to fluoxetine alone.