Assessing the Clinical Efficacy of Sildenafil for the Treatment of

Female sexual dysfunction (FSD), in-cluding a common subclass referred to as female sexual arousal disorder (FSAD), is a highly complex poorly un-derstood phenomenon across women of all ages. Data from the 1999 National Health and Social Life Survey suggest that sexual dysfunction among females is more common (43%) than it is among men (31%).1 The prevalence of FSD was found to be higher in young women, linked to being single, having higher rates of partner turnover, and having periods of sexual inactivity. Other demographic fac-tors such as having low educational attain-ment and deteriorating social position are also positively linked to the development of FSD. In addition, black women have higher rates of low sexual desire compared with white women, who tend to report higher rates of sexual pain. A 2008 cross-sectional survey assessing women aged 30–70 found a prevalence of low sexual desire of 26.7 % for premenopausal wom-en to 52.4 % for women who are naturally menopausal.2 In another 2008 cross-sec-tional survey, the prevalence of any sexual problem was 44.2 % (43.6–44.8%).3 FSD was described using a linear model developed in the 1960s by Mas-ters and Johnson with 4 phases of sexual response—excitement, plateau, orgasm, and resolution— and was based on the observation of middle-class couples.4 However, this model more accurately depicts male sexual function as opposed to female, as it heavily emphasizes what occurs genitally during sexual intercourse.5 A newer, circular model proposed for women incorporates emotion-al intimacy, emotional and physical satisfaction, and sexual desire. This model suggests that sexual desire does not necessarily occur before sexual arousal, and many wome