Men Should Think Twice Before Taking These Two Medications Together

For men living with erectile dysfunction, oral phosphodiesterase-5 inhibitors (PDE5Is) — like Viagra — are likely to be the first treatment suggestion from your doctor (per Sexual Medicine). Since Viagra first arrived on the scene in the late '90s, over 23 million patients have been prescribed the medication, according to 2005 research published in the International Journal of Clinical Practice. If you are among these 23 million+ men, you'll want to exercise caution if you're also taking nitrate vasodilators for coronary artery disease (CAD).

More Americans have coronary artery disease than any other type of heart disease, explains the U.S. Centers for Disease Control and Prevention (CDC). When plaque begins to take over our artery walls, blood has less space in which to flow freely which can lead to blockages in the long run. While symptoms of CAD can include lightheadedness, nausea, or shortness of breath, chest pain (known as angina) is the most common symptom experienced by patients. Nitrates are prescription medications that can help alleviate this chest pain by dilating the arteries and boosting circulation (per St. Luke's). People with heart disease sometimes take these drugs before having sex to ward off angina symptoms. However, combined use of nitrates with PDE5Is could potentially be life-threatening, according to 2024 research findings published in the Journal of the American College of Cardiology.

In the study, researchers looked at patient data from 2006 to 2013 of Swedish men diagnosed with stable coronary artery disease. Out of 61,487 men who had been treated with nitrates, 5,710 of these patients were taking nitrates along with PDE5I medications. Over the course of a nearly six-year average follow-up period, the results showed that taking nitrates and PDE5Is increased the risk of patient death, including cardiovascular death and noncardiovascular mortality. The greatest number of deaths were seen in relation to circulatory diseases.

The researchers explained that one of the risks associated with the combined use of nitrates and PDE5Is is hypotension, as both drugs cause decreases in patient blood pressure. Researchers from a 2001 article published in the Journal of Family & Community Medicine outline how hypotension can result in death if a patient's blood pressure gets too low too fast. For this reason, the researchers advised against giving ED drugs like Viagra to patients taking nitrates, particularly if a person has just taken a PDE5I. This doesn't mean that men diagnosed with coronary artery disease are left to deal with erectile dysfunction on their own, however. Some research alternatively suggests that while hypotension is a potential risk associated with the simultaneous use of nitrates and PDE5Is, the timing of the drugs may make a difference (per HealthDay).

Researchers from a 2022 study published in the Annals of Internal Medicine tracked health data from Danish male patients over the course of 18 years. By the end of the study, the number of men taking nitrates for ischemic heart disease who were also using PDE5Is was 20 times greater in 2018 than in the year 2000. The researchers found no relationship between the combined use of the medications and adverse cardiovascular effects.

The researchers attributed this to the fact that the timing of these medications is usually staggered rather than being taken together. "The nitrates are usually taken in the morning and the ED drugs you usually take in the evening, time enough that [the] drug interaction is not relevant," Dr. John Osborne, director of State of the Heart Cardiology, told HealthDay. While experts acknowledge that this does not completely eradicate the risk of hypotension, waiting to take nitrates until after PDE5Is have worked their way out of the body may reduce this risk. For example, this is how long the effects of Viagra typically last. Just be sure to speak to your doctor first to determine whether it is safe for you to take both drugs under your specific circumstances.