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  • People with cardiovascular disease who took an erectile dysfunction (ED) drug and a medication for angina, or chest pain, had a higher risk of early death.
  • The ED drugs examined in the study are phosphodiesterase type 5 inhibitors (PDE5i), sold under the brand names Viagra, Levitra, Cialis and others.
  • People taking both of these types of medications should talk to their doctor about stopping one or both of the medications, or possible alternative treatments.

A new study finds that Viagra, Cialis, and other similar types of medication are linked to a higher risk of cardiac issues for people who also take medication for chest pain.

Phosphodiesterase type 5 inhibitors (PDE5i) — sold under the brand names Viagra, Levitra, Cialis and others — are a common treatment for erectile dysfunction (ED) in people with cardiovascular disease.

However, people prescribed both a PDE5i for ED and a nitrate for angina (chest pain) had a higher risk of heart failure, early death, and other negative health outcomes, a new study shows.

“Physicians are seeing an increase of requests for erectile dysfunction drugs from men with cardiovascular diseases,” said senior study author Dr. Daniel P. Andersson, associate professor at Karolinska Institutet in Stockholm, Sweden, in a news release.

“While there is a positive association of ED medication for men with cardiovascular disease, patients taking nitrates may experience an increased risk of negative health outcomes,” he said.

The study was published Jan. 15 in the Journal of the American College of Cardiology.

The use of PDE5i treatment in people with cardiovascular disease and ED has been controversial, the authors of the new paper write. These drugs can affect blood flow, disrupt the lining of the blood vessels, and cause oxidative stress.

In addition, use of a PDE5i and nitrate together is not recommended, because both types of drugs can cause drops in blood pressure, but through different mechanisms. In spite of this, some research has found that the number of people prescribed both types of drugs is growing.

In the new study, researchers examined whether men with cardiovascular disease who were prescribed both drugs had a higher risk of certain cardiovascular outcomes.

The study included 61,487 men who had a history of a myocardial infarction (heart attack) or percutaneous intervention (treatment to open a blocked artery, also known as revascularization) from 2005 to 2013. The data came from the Swedish Patient Registry.

In addition, participants filled at least two prescriptions for nitrates — sublingual nitroglycerin or oral nitrates — during that time. Some participants also filled at least two prescriptions for a PDE5i —sildenafil, vardenafil, tadalafil or a combination of those.

Among these men, 55,777 were treated with nitrates alone, and 5,710 were treated with nitrates and a PDE5i. Researchers followed nitrate-only users for an average of 5.7 years, and PDE5i and nitrate users for an average of 3.4 years.

The average age of the nitrate-only users was 70 years, and the average age of men treated with a PDE5i and nitrate was 61 years.

Researchers examined medical data to see how many men died early from any cause, or from a cardiovascular or other cause; or had a heart attack, heart failure, or any major cardiovascular event; or needed cardiac revascularization.

People taking both a PDE5i and nitrate had a higher risk of all of those health outcomes, compared to those taking a nitrate alone, the study showed.

However, few of these negative health events occurred 28 days after participants filled the prescription for a PDE5i, “indicating a low immediate risk for any event,” the researchers wrote.

Dr. Cheng-Han Chen, interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, Calif., wasn’t surprised by the study’s findings.

Chen was not involved in the study.

“We have known for a long time that using a PDE5i along with nitrates can result in an unsafe drop in blood pressure,” he told Healthline. “This study clearly confirms that this combination can result in increased risk of cardiovascular events and even mortality.”

One of the limitations of the study is that researchers did not know if patients took the medications that they were prescribed, or how often — only that they filled the prescription.

The study also included people who had already had a heart attack or underwent revascularization, which makes them high-risk. As a result, the findings may not apply to other groups of people.

In addition, the study is observational, so it cannot show direct cause and effect.

It could be that the increased risk of negative health outcomes is due to both types of medications causing dilation of the blood vessels, said Dr. Yu-Ming Ni, cardiologist and lipidologist at MemorialCare Heart and Vascular Institute at Orange Coast Medical Center in Fountain Valley, Calif.

However, there could be other reasons for the increased rates of early death in people taking both drugs, he told Healthline. For example, the need for a PDE5i may be a sign of more severe cardiovascular disease overall.

“Having erectile dysfunction can be related to poor blood flow in the penis,” said Ni. However, “we know that having blood vessel disease in arteries in one part of the body suggests you’re going to have blood vessel disease in arteries in other parts of the body.”

More research is needed to understand the link between the use of these drugs and the negative health outcomes seen in this study.

In general, people should not be on both medications at the same time, Ni said, something backed up by the new study’s findings.

However, “many men [taking a nitrate] also happen to be on erectile dysfunction medications at the same time, and [your physician] may not be aware of it, for various reasons,” he said. “So it’s really important to bring this to the attention of your physician, if you’re taking both.”

Chen recommends that if you are taking both types of medications, you should talk to your primary care provider or cardiologist about stopping one or both drugs.

In addition, “patients with both ED and angina should know that there are alternatives to nitrates — such as calcium-channel blockers and ranolazine — that can be more safely used if they are taking a PDE5i,” he said.

Researchers examined medical data on men with cardiovascular disease who were prescribed a nitrate for angina, or chest pain. Some were also prescribed a phosphodiesterase type 5 inhibitors (PDE5i) for erectile dysfunction.

Men who were prescribed both types of drugs had a higher risk of dying early, heart attack, and other cardiovascular outcomes, compared to those who were prescribed only a nitrate.

Experts say that, in general, these two types of medications should not be used together. If you are taking both drugs, talk to your doctor about stopping one or both meds, or finding an alternative medication.