MIAMI (AFP) - Popular over-the-counter antacids for treating heartburn, like Prilosec, are linked to a 20 per cent higher risk of heart attack, researchers said on Wednesday.
The study in the journal PLOS ONE was based on a large data-mining study of nearly three million health records, and was carried out by scientists at Stanford University.
The study looked at drugs such as Prilosec, Nexium and Prevacid, which are part of a class of drugs known as proton-pump inhibitors, or PPIs, and are among the world's most widely prescribed drugs, generating some US$14 billion (S$18.8 billion) in annual sales.
About 20 million Americans, or one in every 14 people, use PPIs such as Prilosec (omeprazole) for heartburn, acid reflux or gastroesophageal reflux disease, according to the study.
Until now, they were largely considered to be safe unless taken with the blood thinner Plavix (clopidogrel).
While the study did not prove that antacids cause heart attacks - only that there is an apparent link - researchers believe the problem may involve how the drugs affect the lining of blood vessels.
Another kind of antacid, known as H2 blockers, showed no higher risk of heart attack. These drugs include Zantac and Tagamet.
Researchers urged patients to talk with their doctors before discontinuing any medication.