Severe Diarrhea Risk Linked to PPIs Prompts FDA Warning

Limiting Dose, Duration of Use Can Reduce Threat of Side Effects

February 14, 2012 03:35 pm News Staff

This micrograph depicts Gram-positive Clostridium difficile bacteria from a stool sample culture obtained using a 0.1 micrometer filter.

The FDA is notifying physicians and other health care professionals, as well as patients, that use of proton pump inhibitors (PPIs) may increase the risk of Clostridum difficile-associated diarrhea (CDAD).

According to a Feb. 8 FDA drug safety communication(, CDAD, which is characterized by watery stool, abdominal pain and fever, should be considered in patients taking PPIs who develop diarrhea that does not improve. Some patients develop more serious intestinal conditions after exposure to the bacterium.

AHRQ Resources Focus on Clostridium difficile Infection

The Agency for Healthcare Research and Quality (AHRQ) Effective Health Care Program has completed a systematic evidence review comparing the accuracy of diagnostic tests and the effectiveness of prevention and treatment interventions on Clostridium difficile infection-related patient outcomes in adults.

The full report( can be downloaded from the AHRQ website, as can an executive report summary, clinician and consumer research summaries, and related resources.

"Patients should immediately contact their health care professional and seek care if they take PPIs and develop diarrhea that does not improve," the FDA said in the release. The agency also noted that using the lowest PPI dose and shortest duration of therapy appropriate to the condition being treated can reduce CDAD risk.

PPIs, which reduce the production of stomach acid, are marketed under various brand and generic drug names as prescription and OTC products. A complete list of PPIs can be found at the FDA website(

The agency said it is working with manufacturers to include information about the increased risk of CDAD in PPI product labels. The FDA also is reviewing the risk of CDAD in users of histamine H2 receptor blockers, which are used to manage the same types of conditions PPIs treat.

Physicians and other health care professionals can report adverse events or side effects related to the use of PPIs or other agents to the FDA's MedWatch Safety Information and Adverse Event Reporting Program online( or by phone at (800) 332-1088.