Flibanserin, a 5-HT1A agonist and 5-HT2A antagonist, is approved for treatment of acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women. Insomnia is a common side effect of medications that affect central serotonergic mechanisms. This analysis examined the incidence of insomnia associated with flibanserin and other representative medications that affect central serotonergic systems.METHODS:
Patient-level data from five 24-week, randomized, double-blind, placebo-controlled, studies in premenopausal women with HSDD were pooled to evaluate the incidence, time to onset, and duration of insomnia with flibanserin treatment. Incidence of insomnia was obtained from clinical trial data reported in the prescribing information for a commonly prescribed selective serotonin reuptake inhibitor (sertraline, steady-state treatment), serotonin-norepinephrine reuptake inhibitor (venlafaxine, steady-state treatment), and triptan (sumatriptan, acute treatment).RESULTS:
In the pooled data (flibanserin 100 mg at bedtime, n=1,543; placebo, n=1,905), most patients (88.2%) were white and mean age was 35.8 years. Mean exposure was 139.0 days with flibanserin and 147.4 days with placebo. The incidence of insomnia was 4.9% with flibanserin and 2.4% with placebo. As context, the incidence of insomnia reported for some commonly used medications that affect the central serotonergic mechanisms ranges from <2% to 21%. Median time to onset of insomnia with flibanserin was 11.0 days from drug initiation and lasted for a median duration of 31 days (range, 1-186 days).CONCLUSION:
The incidence of insomnia with flibanserin was 4.9%, toward the lower end of the range seen with other medications with central serotonergic effects; onset was typically within 2 weeks and resolution within 31 days.