NEW YORK (Reuters Health) – Gastric acid suppression by proton pump inhibitors (PPIs) is associated with an increased risk of Clostridium difficile-related diarrhea in hospitalized patients, results of a case-control study indicate.

Dr. Mohammed Aseeri from King Abdul Aziz Medical Center, Jeddah, Saudi Arabia and colleagues identified 94 patients who developed C. difficile-associated diarrhea while hospitalized.

The investigators pair-matched these case patients to control patients for the most common factors predisposing hospitalized patients to C. difficile-associated diarrhea: admission date, antibiotic exposure, gender, age, patient location (medical or surgical unit), and room type at the time of admission.

In the September issue of the American Journal of Gastroenterology, Dr. Aseeri and colleagues report that patients with C. difficile-associated diarrhea were more likely than control patients to receive acid suppressive therapy before admission and continuing during hospitalization — 76.6% versus 42.6%, respectively.

In multivariate analysis, C. difficile-associated diarrhea was associated with the use of PPIs, with an odds ratio of 3.6, and with renal failure (odds ratio, 5.7).

“A potential mechanism for this phenomenon is inhibition of gastric acidity resulting in the loss of a defense mechanism against ingested spores and bacteria,” the investigators suggest.

Dr. David C. Metz notes in an editorial published with the study, that the findings “appear consistent with other similar studies examining the role of PPIs in the development of C. difficile colitis.”

Dr. Metz, from the University of Pennsylvania, Philadelphia, points out that PPI withdrawal in patients who need acid suppression can lead to severe complications.

“Instead of stopping PPIs when patients are admitted to hospital,” Dr. Metz advises, “I propose continuing the therapy at the lowest effective maintenance dose and adhering to careful barrier nursing and hand washing among patients.”

Am J Gastroenterol 2008;103:2308-2313.