The negative effect came only when it was combined with nitrates. In addition to highlighting the need for patients to only take Viagra under medical supervision, Dr. Khandheria says the findings provide important guidance for physicians in how to prescribe Viagra safely. Many heart patients need to take nitrates, and many want to use Viagra. This study shows that they should not be taken together. The old adage of taking a nitroglycerine tablet prior to sexual intercourse falls by the wayside if Viagra is prescribed, since the combination can be lethal.
Doctors prescribe nitrates in various forms to relieve or prevent chest pain, known as angina.
Common forms include nitroglycerine tablets placed under the tongue, sprays, patches or long-acting tablets. Dr. Khandheria says understanding the interaction with Viagra is important because so many heart patients also experience erectile dysfunction. As a result, many heart patients are interested in using Viagra to maintain their quality of life, so we need to know how it interacts with other medications they may be taking. This study shows a potentially life-threatening interaction between Viagra and nitrates. The two drugs interact to reduce blood flow in arteries with critical stenosis, causing a drop in blood pressure, which deprives the heart of oxygen.