This drug is normally prescribed for the treatment of impotence, but does not cause sexual stimulation. Rather, it solves an underlying problem that causes impotence. It enhances nitric oxide-induced relaxation of smooth muscles. This mechanism might be useful in reducing tight anal sphincters in people with anal fissures. Topical gel versions of sildenafil have already been available because they have been used with some success in clinical trials for post-menopausal women with sexual difficulties, as reported in the British Journal of Obstetrics & Gynecology
, and The Journal of Reproductive Medicine
An article in Diseases of the Colon and Rectum
reported on a small trial conducted in Marbella, Spain, and the Southeast Georgia Regional Medical Center, Brunswick, Georgia. Researchers treated 19 people with chronic anal fissures with a topical sildenafil cream (which is not available in the United States). The data reported maximum resting anal sphincter pressures dropped approximately 18% in all patients. Only one did not achieve a reduction of more than 10%. These declines occurred within three minutes of applying sildenafil. The most common side effect was transient anal itching or burning, reported in 26%. Although this drug significantly reduced anal sphincter pressure in this small group, researchers believe that trials of larger groups are needed.