Erectile dysfunction (ED) is often believed by men to be a side effect of drugs prescribed to treat high blood pressure and high cholesterol, which promote the development of heart disease. But a new study from scientists at McMaster University in Canada examining the effects of such drugs finds that men taking them have nothing to worry about.
As men grow older, ED become more common. It affects 40 percent of men older than 50 and can be a sign of health problems like vascular disease or nerve damage from diabetes. For men with both ED and heart disease risk factors like high blood pressure and high cholesterol, the idea that the medications they take to treat these risk factors are causing their ED is apparently a misconception.
"Previous research suggests that cardiovascular risk factors such as high blood pressure and cholesterol increase the risk of ED, but there has been little research examining whether modifying these risk factors can impact its development," explained lead investigator Philip Joseph, MD.
In Joseph’s new study, he examined the impact of statins, which lower cholesterol, and a combination drug called candesartan/Hydrochlorothiazide (HCTZ), which lower blood pressure, on erectile function. HCTZ is a diuretic drug (it prevents too much salt absorption) and candesartan is an “angiotensin II receptor antagonist” which means that it improves blood flow by preventing narrowing of the blood vessels. Together, these two drugs treat high blood pressure.
Researchers conducted their study in two thousand men with three experimental groups: men taking a drug called rosuvastatin to lower cholesterol, men taking candesartan/HCTZ to lower blood pressure, and men taking both. Each group was compared to its own placebo control group. The control groups were given placebos - pills with no actual medication in them - to factor in a phenomenon that sometimes occurs, the placebo effect. This is where study subjects taking a placebo feel like they are getting better or having a desirable effect because they believe they are taking medicine. Neither the study subjects nor the study researchers knew which participants received the placebo and which received the actual drugs.
Each participant filled out an erectile function questionnaire, “The International Index of Erectile Function,” which is a validated survey to assess erectile function. They completed the questionnaire at the beginning of the study and after an average follow-up of about six years.
The results were straightforward; none of the men taking any combination of drugs reported a significant change in erectile function compared to each placebo control group.
"Men who develop ED while on such medications commonly attribute their symptoms to the medications,” Joseph said. “Our findings suggest that these two medications do not negatively impact erectile function, which should be reassuring to men who are taking them."
The present study was published in the Canadian Journal of Cardiology.