Popular drugs that effectively ease acid reflux may result in a life-threatening side effects — heart attack, heart failure, and sudden cardiac death. Common examples of these heartburn medications include Prilosec (omeprazole), Nexium (esomeprazole), and Prevacid (lansoprazole).

Stanford University researchers have recently discovered these drugs — known as proton pump inhibitors or PPIs —can cause the constriction of blood vessels. And their regular use can lead to hypertension and potential heart attacks.

PPI Study Suggests Increased Heart Attack Risk

On June 10, the journal PLOS One published research from a team of doctors at Stanford University who used data mining to examine the records of 3 million patients to evaluate the potential risk of heart attacks associated with Prilosec and other PPIs. This recent study reveals evidence that common heartburn medication taken by more than 100 million people every year is associated with a greater risk of heart attacks.

After combing through 16 million electronic records of 2.9 million patients in two separate databases, the researchers found that people who take the medication to suppress the release of stomach acid are 16 to 21 percent more likely to suffer from a myocardial infarction, commonly known as heart attack.

Because of its design, the study could not show cause and effect, but the researchers did claim that if their technology had been available, “such pharmacovigilance algorithms could have flagged this risk as early as the year 2000.”

The link between the drugs, known as proton pump inhibitors, and heart attacks is strong enough that “we do think patients should think about their risks and benefits and should discuss their risk with their doctors,” said Nicholas Leeper, an assistant professor of cardiovascular medicine and vascular surgery at Stanford, and one of the authors of the study.

Leeper said the Food and Drug Administration “should be aware of these findings” but agreed that only a large, prospective clinical study could establish whether the heartburn drugs are causing more heart attacks.

What are Proton Pump Inhibitors?

Proton pump inhibitors (PPIs) such as Nexium, Prilosec and Prevacid are among the most widely used acid reflux in the world. According to the Stanford study, an estimated 113 million prescriptions for the drugs are written for them around the world each year.

In the United States, 21 million people used one or more of these heartburn medications by prescription in 2009. When over-the-counter versions are added, worldwide sales total $13 billion annually, according to the paper.

Proton pump inhibitors, like Prilosec, work by blocking the production of stomach acid. They do this by shutting down a system in the stomach known as the proton pump.

Proton pump inhibitors are used in the treatment of GERD, stomach and duodenal ulcers, erosive esophagitis, and Zollinger-Ellison syndrome. Doctors may prescribe PPIs alone, or in combination with antacids. PPIs may also be used in combination with certain antibiotics when treating a bacterial infection of the stomach, which is thought to be one of the main causes of recurring stomach ulcers.