About six months ago, in a historical and controversial move, the Food and Drug Administration approved flibanserin (Addyi), the first prescription drug designed to boost a women’s libido. The drug’s approval was considered a victory for a lobbying campaign that has argued for gender equality, while a coalition of health providers contended that flibanserin works minimally better than a placebo and has substantially harmful side effects.
On Monday, researchers reported follow-up results: The drug is said to increase satisfying sexual encounters by close to one a month, on average.
In the new study, published in JAMA Internal Medicine, researchers found that benefits were slightly more modest than those submitted to the FDA during the approval process. The findings came from a first pooled analysis of five published and three unpublished clinical trials, of nearly 6,000 women. Treatment with flibanserin, they concluded, resulted in “one-half of an additional sexually satisfying encounter per month.” (The study did not define what “one-half” of a sexually satisfying encounter was).
When the drug was submitted to the FDA for approval last year, it was based on original findings from three clinical trials that found that women taking flibanserin had an average of about one additional satisfying sexual encounter a month, in addition to the two to three they were already having. “That result lifted the benefits above the bar of being scientifically meaningful, but barely,” wrote The New York Times. “Still, it was enough for the agency’s approval.”
Flibanserin was approved last June, after twice being rejected by the FDA. The drug from Sprout Pharmaceuticals aims to increase women’s sex drive by altering brain chemistry.
Side effects of the drug include sleepiness, dizziness, fatigue and nausea, and these increase with alcohol consumption.
In June, Sprout said it will not advertise on radio or television for 18 months after the drug’s approval and instead, focus its marketing on doctors, not consumers.
The study authors wrote in JAMA Internal Medicine: “With nearly 90 percent of American physicians indicating that they would prescribe an approved hypoactive sexual desire disorder pharmacological product over available nonpharmacological treatments, the need for sound evidence on the efficacy and safety profile of flibanserin is evident.
“The findings of this review suggest that the benefits of flibanserin treatments are marginal…Before flibanserin can be recommended in guidelines and clinical practice, future studies should include women from diverse populations, particularly women with a history of somatic and psychological comorbidities, medication use, and surgical menopause.”
In a commentary published alongside the study, Dr. Steven Woloshin and Dr. Lisa M. Schwartz, professors at Dartmouth Medical School wrote, “The flibanserin saga is unsatisfying. The FDA approved a marginally effective drug for a non-life-threatening condition in the face of substantial — and unnecessary — certainty about its dangers. Women with distressing sexual desire problems need good treatments. We all need a drug approval process that delivers good decisions based on adequate evidence.”
Filed Under: Drug Discovery