Cialis Failed To Prevent Erectile Dysfunction After Radiation: Study

A new study suggests that Cialis is not effective in helping men undergoing radiation treatment for prostate cancer avoid erectile dysfunction, which is common side effect of the cancer treatment. 

According to findings published by the Journal of the American Medical Association (JAMA) on April 2, researchers indicate that the impotence drug is no more effective at improving erectile function and sexual satisfaction among men who were treated with radiation than a placebo.

Men diagnosed with prostate cancer commonly undergo radiation therapy, which carries a risk of erectile dysfunction in nearly half of the patients, forcing many to turn to erectile dysfunction (ED) drugs, like Cialis.

Dr. Thomas Pisansky and a team of researchers from the Mayo Clinic in Rochester, Minnesota, tested 242 male patients with prostate cancer and intact erectile function. During the Radiation Therapy Oncology Group Randomized Clinical Trial, which was conducted at 76 different medical sites in the U.S and Canada, researchers gave half of the men 5 mg of Cialis daily and the other half a placebo. The dose was started at the same time their radiation treatment began. The trial was conducted between November 2009 and February 2012.

Participants reported erectile function before treatment began, at two weeks, four weeks, between 20 and 24 weeks, between 28 and 30 weeks and one year after treatment.

The double-blind, placebo-controlled trial found 79% of patients treated with Cialis maintained normal erectile function, while 74% of patients treated with placebo retained normal erectile function as well; a difference of only five percent.

Researchers concluded Cialis does not prevent erectile dysfunction in patients undergoing radiation treatment anymore than a placebo did. It did not improve overall sexual function or satisfaction, according to patients and their partners.

Radiation is the most common treatment for prostate cancer, however erectile dysfunction is a side effect in more than 40% of patients. Cialis is commonly used to treat erectile dysfunction after prostate cancer treatment.

The drug stays in the blood stream much longer than other erectile dysfunction medications and is potentially active for a longer amount of time. The Cialis website indicates it may stay in a patients’ blood stream for up to two days. It is thought to be effective by improving blood vessel functioning.

Doctors believe the cause of erectile dysfunction after radiation is linked to blood vessel damage. Yet, when given Cialis, radiation patients did not experience increased erectile functioning.

Researchers warn that the findings of the study do not support daily use of Cialis to prevent erectile dysfunction in radiation therapy patients.

Cialis is currently marketed as a treatment for erectile dysfunction and for benign prostatic hyperplasia, not as a prevention for either disease. It is the only drug FDA approved for once-a-day dosing for the problem.

Erectile dysfunction medications grow in popularity each year. Sales for Cialis reached nearly $2 billion in 2012.