The pharmacodynamic effects of combined administration of flibanserin and alcohol.
Level 2 - randomized trial
Randomized crossover interaction trial and pooled analysis of randomized trials
PubMed 28608926 · doi:10.1111/jcpt.12563
What was done
Researchers evaluated the interaction between flibanserin and alcohol using two data sources: a phase 1 randomized crossover trial in 25 healthy adults (23 males, 2 females) who received flibanserin 100 mg or placebo with or without ethanol (0.4 g/kg or 0.8 g/kg) evaluating vital signs, sedation, adverse events, and AUC(0-4); and a pooled analysis of five phase 3 randomized trials in premenopausal women with hypoactive sexual desire disorder taking flibanserin 100 mg daily (n=1543) or placebo (n=1905).
What was found
In the phase 1 study, the incidence of hypotension and syncope increased when flibanserin was coadministered with ethanol. Sedation scores on a visual analogue scale increased from baseline by 20% with flibanserin plus 0.4 g/kg ethanol and by 27% with flibanserin plus 0.8 g/kg ethanol at 4 hours post-dose. In the pooled phase 3 analysis, baseline alcohol use was reported by 58.2% of flibanserin and 63.6% of placebo participants; flibanserin-treated patients who consumed alcohol experienced fatigue and dizziness more frequently than non-drinkers (exact event rates were not provided in the abstract).
Why it matters
These findings describe the pharmacodynamic basis for warnings regarding coadministration of flibanserin and alcohol, demonstrating increased risk for sedation, hypotension, and syncope.
Limits
The dedicated phase 1 interaction study was small (n=25) and conducted almost exclusively in men (23/25), despite flibanserin being indicated for premenopausal women. In the phase 3 pooled analysis, alcohol consumption was based on baseline self-report rather than controlled administration, and exact adverse event rates were omitted from the abstract.
Cited by
- contradicts Clinical trials for drugs exclusively prescribed to women are conducted on men because women cannot tolerate the drugs.