Vaginally Administered Danazol: An Overlooked Option in the Treatment of Rectovaginal Endometriosis?

Danazol has been used in the treatment of endometriosis and heavy menstrual bleeding for more than 40 years. This medication has both central antigonadotropic actions and direct atrophic effects on endometriotic tissue. Although it demonstrates a high-efficacy profile, the associated side effects have resulted in limited usage. Vaginal administration of the drug may prove favourable specifically in rectovaginal endometriosis. This targeted mode of delivery is associated with a significant reduction in both pain symptoms and nodule size. The relative persistence of these therapeutic benefits is likely related to the direct tissue effects after absorption through the vaginal mucosa. Vaginal administration would also limit systemic propagation of danazol and thus should minimize androgenic side effects. Use of vaginal danazol also improves heavy menstrual bleeding and may even restore fertility in some patients. In this review we provide a critical analysis of the existing literature on the use of vaginal danazol.