Effects of Alcohol Administered With Flibanserin in Healthy Premenopausal Women: A Randomized, Double-Blind, Single-Dose Crossover Study

Introduction: Flibanserin is approved in the United States and Canada for the treatment of hypoactive sexual desire disorder in premenopausal women. Aim: The purpose of this trial was to evaluate the safety of concomitant administration of flibanserin with alcohol. Methods: In this single-center, randomized, double-blind, single-dose, crossover study, participants were randomly assigned to 1 of 12 sequences to receive each of 7 treatments: flibanserin 100 mg or placebo with ethanol 0.2 g/kg, 0.4 g/kg, or 0.6 g/kg, or flibanserin 100 mg only. Treatments were administered using a worst-case approach that included morning dosing and consumption of alcohol within 10 minutes. Main Outcome Measure: The primary end point was the proportion of participants who experienced dizziness, syncope, or hypotension. Safety end points included orthostatic vital signs. Results: The study included 96 premenopausal women (mean age 31 +/- 8 years). The incidence of dizziness for ethanol + flibanserin was 39.8% for ethanol 0.6 g/kg, 34.1% for 0.4 g/kg, and 27.4% for 0.2 g/kg compared with 31.1% for flibanserin without ethanol. Based on the available vital signs data, there was no effect of ethanol concentration on orthostatic blood pressure, vertigo, or hypotension; no instances of syncope were observed. The overall incidence of adverse events (AEs) was similar when flibanserin was administered alone (96.7%) or with ethanol (90.5-97.6%). Clinical Implications: Consumption of the tested amounts of alcohol (0.2-0.6 g/kg) does not have an additive effect on the AE profile of flibanserin 100 mg in healthy premenopausal women. Strengths & Limitations: Strengths include the study population (premenopausal women, as indicated for flibanserin) and range of ethanol doses. Limitations include the morning dosing of study medication, which is inconsistent with the bedtime dosing recommended for flibanserin, and the method of handling missing vital sign measurements. Conclusion: Co-administration of flibanserin 100 mg with varying doses of ethanol resulted in few AEs of special interest, with no notable alcohol dose response. However, a significantly greater percentage of participants administered flibanserin with 0.6 g/kg and 0.4 g/kg of alcohol were characterized as "Participants in Whom Standing Blood Pressure Was Not Obtained" compared with participants administered flibanserin alone. Copyright (C) 2019, International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.