A recent study quantified how much the treatment effect of pharmacologic modalities for female sexual dysfunction could be attributed to the placebo effect.
More efficacious treatment is needed for all areas of female sexual dysfunction. That is the conclusion of a meta-analysis in which investigators looked at the current evidence on the efficacy of various pharmacologic modalities to treat the disorder.
“This study highlights the limitations of the current medications available to women with female sexual dysfunction,” said lead author, James M. Weinberger, MD, a resident physician, Department of Urologic Surgery, UCLA Health, Los Angeles, CA.
Published in Obstetrics & Gynecology, the research comes on the heels of a previous study by Weinberger and colleagues in which they systematically reviewed the efficacy of various pharmacologic treatments for female sexual dysfunction. Results of that study, said Dr. Weinberger, underscored that studies on female sexual dysfunction lag far behind those on male sexual dysfunction and emphasized the lack of current treatments for female sexual dysfunction.
Closer look at the current study
Weinberger and colleagues undertook the current study because they noticed a marked placebo response in trials of female sexual dysfunction when they were undertaking the systematic review of their previous study.
In assessing the efficacy of pharmacologic treatments for female sexual dysfunction in the current study, the investigators therefore specifically reviewed randomized studies in which pharmacologic modalities for female sexual dysfunction were compared to the placebo effect. The overall objective of the current study was to quantify how much the treatment effect of these modalities could be attributed to the placebo effect.
Studies were included in the meta-analysis only if they were randomized clinical trials with Level I evidence, had a blinded placebo arm, and included only women with clinical pretreatment for female sexual dysfunction. Female sexual dysfunction included four areas of dysfunction: hypoactive sexual desire disorder, arousal disorder, orgasmic disorder, and sexual pain disorder.
Based on these inclusion criteria, the meta-analysis included a total of 8 studies including 1,723 women who received placebo and 2,236 who received one of various pharmacologic treatments (ie, flibanserin, bupropion, onabotulinum toxin A, intravaginal prasterone, intranasal oxytocin, ospemifene, and bremelanoted).
The study found that the placebo effect in these studies accounted for 67.7% of the treatment effect for the agents used to treat sexual dysfunction. Using the Female Sexual Function Index, a 19-item tool that assesses six domains of sexual functioning, the study showed that sexual dysfunction in women receiving placebo improved 3.62 (95% CI, 3.29-3.94) compared to 5.35 (95% CI, 3.29-3.94) in women receiving a pharmacologic treatment.
Dr. Weinberger reiterated that these results underscore the limitations of current pharmacologic agents to treat female sexual dysfunction. Specifically, the strong placebo effect shows that current treatment approaches to female sexual dysfunction fail to address the multifactorial nature of the disorder and instead treat only a single aspect of it.
“If an efficacious treatment is to be found, the treatment must address all domains of female sexual dysfunction as well as the biopsychologic component of the female sexual experience,” state the authors in the study’s conclusion.