Sexual function assessment and the role of vasoactive drugs in female sexual dysfunction

Despite the high prevalence of sexual problems in women, relatively few clinical trials have been conducted to date of either vasoactive drugs (e.g., sildenafil, apomorphine) or hormone replacement therapy or a combination of the two on sexual function problems in women. This article addresses the key conceptual and methodological issues to be addressed in clinical trials, particularly in the area of response outcomes or efficacy assessment. In particular, the use of self-report questionnaires and event-log or diary-based responses as primary outcome variables or endpoints in clinical trials is considered. Physiological measures, such as the vaginal photoplethysmograph probe, are being used in early proof of concept studies. There may be some value in the use of these measures for proof-of-concept and early dose-finding studies. Physiological measures are not used in large-scale, multicenter clinical trials, where patient-based or diary measures are clearly preferable. Clinical trials in this area should also make use of the new consensus classification system for female sexual dysfunction in determining inclusion and exclusion criteria for the trial.