Taking flibanserin with alcohol does not appear to add to adverse events, according to a recent alcohol-interaction study.
Approved in the United States and Canada, flibanserin is an oral medication for the treatment of acquired generalized hypoactive sexual desire disorder (HSDD) in premenopausal women.
Women with HSDD have a persistent, distressing lack of or decrease in sexual interest.
A previous alcohol-interaction study was conducted as part of the drug review procedure for approval by the U.S. Food and Drug Administration (FDA). At that time, concerns about hypotension (low blood pressure) and syncope (fainting) prompted the FDA to require a boxed warning on packages of flibanserin, indicating a contraindication with alcohol. (In August 2019, contraindication information was changed, and patients were advised to wait at least two hours between alcohol intake and flibanserin use.)
However, this study involved mostly male participants, who were not the target population for flibanserin. In addition, the drug was administered in the morning, in contrast to its recommended bedtime dosing instructions.
Because of these issues, the FDA required another alcohol-interaction study, one that included premenopausal women – the drug’s target population. The FDA wanted this study to investigate the effects of flibanserin and different alcohol doses on dizziness, hypotension, and syncope along with safety and tolerability.
The current study involved 96 healthy, premenopausal women between the ages of 18 and 45 (average age 31). Eighty-four women completed the study.
The participants received 7 treatments of various combinations:
- Flibanserin 100 mg with 0.6 g/kg, 0.4 g/kg, or 0.2 g/kg of ethanol
- A placebo with 0.6 g/kg, 0.4 g/kg, or 0.2 g/kg of ethanol
- Flibanserin alone
Typically, such ethanol doses are enough to induce relaxation and mild impairment.
Each treatment lasted for two days. After an overnight fast and light snack, each woman took flibanserin or the placebo in the morning, followed by ethanol within 10 minutes. Orthostatic vital signs were assessed periodically afterward. Treatments were separated by a 7-day washout period.
The researchers found that the studied ethanol doses “did not have an additive effect on the [adverse event] profile of flibanserin.” Women who received flibanserin with 0.6 g/kg of ethanol were more likely to experience dizziness, but the effect was not statistically significant. The incidence of dizziness found with flibanserin and smaller doses of ethanol was similar to that of flibanserin alone.
One participant experienced hypotension and one had vertigo. There were no cases of syncope.
The authors acknowledged several limitations. For example, the study participants took flibanserin in the morning instead of at bedtime, the recommended dosing time. This study protocol was followed so that the women’s vital signs could be assessed at various intervals after dosing, but results could be different in “real-world” situations.
Also, about 2% of orthostatic vital sign assessments were not taken because of low blood pressure, dizziness, or other reasons, such as vomiting or “feeling drunk.” This situation was more common among women who took flibanserin with 0.6 g/kg or 0.4 g/kg of ethanol compared to women who took flibanserin only.
The study was published online in November in the Journal of Sexual Medicine.
The Journal of Sexual Medicine
Simon, James A, MD, et al.
“Effects of Alcohol Administered With Flibanserin in Healthy Premenopausal Women: A Randomized, Double-Blind, Single-Dose Crossover Study”
(Full-text. Published online: November 14, 2019)