Acid-blocking drugs linked to C. diff infection

A class of antacids known as proton pump inhibitors (PPIs) may increase the risk of severe diarrhea caused by Clostridium difficile bacteria, the FDA has announced. The advisory comes after the agency s review of 28 observational studies, which found that the rate of C. difficile infection was from 1.4 to 2.75 times higher among patients who had been taking PPIs such as Nexium, Dexilant, Prevacid, and Prilosec, among others.

Although antacids can relieve the pain of heartburn and help to heal ulcers, the resulting reduction of stomach acid lowers the body s defense against some pathogens. Normally, the stomach is acidic enough to kill bacteria like C. difficile. However, if the stomach isn t adequately acidic, these bacteria will pass into the intestines and may cause a serious infection. (Yet as ACSH advisor Dr. John Dunne points out, C. difficile infections most commonly result from antibiotics, which can reduce the normal intestinal flora, allowing C. difficileto flourish.)

These acid-blockers are so commonly used that we need to increase awareness of their association with C. difficile infections, says ACSH's Dr. Gilbert Ross. Doctors need to be more judicious when deciding whether to recommend PPIs to patients who are especially susceptible to infection, such as the elderly and those who are immunocompromised. And that concern should be extended to their patients taking this class of drug OTC as well.

But as a rule, ACSH s Dr. Josh Bloom adds, these drugs are among the safest in the pharmacy. The minimal risk of of a C. difficile infection should be weighed against the many benefits of acid suppression in patients suffering from acid-peptic disease.