Study to Investigate Effect of Sildenafil on Clitoral Engorgement as Measured by Magnetic Resonance Imaging (MRI) in Pre-menopausal Women With Female Sexual Arousal Disorder

Inclusion Criteria: * Pre-menopausal women aged 18-45 with a primary diagnosis of Female Sexual Arousal Disorder for at least 6 months prior to entering the study. The FSAD could have been associated with female orgasmic disorder (FOD) and/or superficial or introital dyspareunia. Exclusion Criteria: * Subjects with hypoactive sexual desire disorder. * Subjects not using an acceptable mean of contraception for the duration of the study. * Subjects who were prescribed and/or taking medication which were contraindicated or cautioned with concomitant intake of sildenafil.