For men with erectile dysfunction and low testosterone who do not respond to Viagra* (sildenafil) alone, the supplemental use of AndroGel** (testosterone gel) improves erectile function and overall sexual satisfaction, according to a NewYork-Presbyterian Hospital/Columbia University Medical Center study.

Dr. Ridwan Shabsigh, associate professor of urology at Columbia University College of Physicians & Surgeons and director of the New York Center for Human Sexuality at NewYork-Presbyterian Hospital/Columbia was the lead investigator in the study, which is published in the August issue of the Journal of Urology.

\"Our data support the potential benefits of a combination therapy with testosterone gel for men with erectile dysfunction and low testosterone who find sildenafil by itself ineffective,\" said Dr. Shabsigh. \"When assessing erectile dysfunction, doctors and patients should consider using a simple blood test to determine if low testosterone is a contributing factor. If the root cause is low testosterone, sildenafil alone won’t fix the problem.\"

It is estimated that four to five million American men have low testosterone. Furthermore, low testosterone, also called hypogonadism or \"low T,\" affects about one in 10 men between the ages of 40 and 60. Low testosterone may lead to decreased libido, erectile dysfunction, osteoporosis, reduced lean body mass, depressed mood and fatigue.

Sildenafil enhances the effects of nitric oxide, a chemical in the body that allows increased blood flow to the penis during sexual stimulation. \"Research suggests nitric oxide may be dependent on testosterone to function properly,\" said Dr. Shabsigh. \"While further studies are needed, this concept may explain why testosterone replacement therapy could help hypogonadal men who do not respond to sildenafil.\"

In the trial, 75 hypogonadal men (18 to 80 years old) were randomized to testosterone gel plus sildenafil versus placebo plus sildenafil. Participants were in a stable heterosexual relationship. Ninety-one percent had experienced erectile dysfunction for at least one year prior to the study. All participants had testosterone levels in the low to low/normal range (