Evaluation of Flibanserin Safety: Comparison with Other Serotonergic Medications

Flibanserin, a multifunctional serotonin agonist and antagonist, is approved by the U.S. Food and Drug Administration (FDA) for treatment of acquired, generalized hypoactive sexual desire disorder in premenopausal women. During the FDA's review of flibanserin, concerns were raised about the risks of hypotension, syncope, and sedation-related adverse events, which increase with alcohol use. Based on the results of an alcohol challenge study, the FDA required a boxed warning and alcohol contraindication in the flibanserin prescribing information, as part of a risk evaluation and mitigation strategy program.

To evaluate the adverse event profile of flibanserin in the context of that seen with other medications that affect serotonin in the brain and are commonly prescribed for women.

This was a review of data provided in the product prescribing information for flibanserin, selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, other serotonergic antidepressants, and triptans.

The incidence of adverse events was assessed.

The incidences of hypotension, syncope, and sedation-related adverse events (eg, dizziness, somnolence, fatigue) in studies of flibanserin were within the ranges observed for serotonergic antidepressants; the rates of these adverse events were generally lower with triptan medications. Other flibanserin-associated adverse events (eg, nausea, insomnia, dry mouth) occurred more commonly in patients taking antidepressant medications.

Although medications that affect the serotonin system have varying adverse event profiles (likely mediated by differences in serotonin-related mechanisms of action, specific brain structures affected, and effects on other neurotransmitter systems), the occurrence of central nervous system-related adverse events was not dissimilar between flibanserin and serotonergic antidepressants. Kingsberg SA, McElroy SL, Clayton AH. Evaluation of Flibanserin Safety: Comparison with Other Serotonergic Medications. Sex Med Rev 2019;7:380-392.