Viagra, Testosterone or Both in Erectile Dysfunction?
Many men are found to have "borderline" or low testosterone levels as they age. And one in three men older than 50 years experience some degree of erectile dysfunction (ED). Because ED and low testosterone levels frequently coexist, and because testosterone is important in the regulation of libido (sex drive or desire), some physicians have prescribed both Viagra or similar drugs and testosterone replacement for men who have both ED and low testosterone levels.
Researchers at Boston University studied 140 men with ED and low testosterone. All subjects were given Viagra and testosterone levels were remeasured after approximately one month of treatment. Interestingly, treatment with Viagra alone resulted in an approximately 40% increase in blood testosterone levels (from an average of about 250 ng/dL to 350 ng/dL).
The men were then divided into two groups. In one group, topical testosterone gel was added daily and in the other, a matching placebo gel was dispensed. Testosterone treatment resulted in an increase in the average blood testosterone level to about 650 ng/dL, well within the normal range. Blood testosterone levels did not change in men given the placebo gel.
The study was conducted in a double-blind fashion (neither the subjects nor the physicians conducting the trial new which men were receiving testosterone and which were receiving placebo). Over the fourteen week course of the study, the men were surveyed regarding sexual desire, frequency of sexual activity, frequency of erectile dysfunction, satisfaction with sexual encounters, marital satisfaction and overall quality of life.
In both groups, the frequency of sexual intercourse increased during the study. There were no differences between the two groups in any measure of sexual desire, frequency, success, satisfaction or quality of life.
The authors conclude that in men with ED who had low testosterone levels, the addition of testosterone provided no benefit beyond treatment with Viagra alone.
Spitzer M, et al. Effect of Testosterone Replacement on Response to Sildenafil Citrate in Men With Erectile Dysfunction: A Parallel, Randomized Trial. Ann Intern Med. 2012;157(10):681-691. doi:10.7326/0003-4819-157-10-201211200-00004
Reviewed / Posted by: Scott W. Yates, MD, MBA, MS, FACP