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Proton Pump Inhibitors do not raise risk of hospitalization for C. difficile in elderly patients taking antibiotics


A new study from the Institute for Clinical Evaluative Studies (ICES) shows that proton pump inhibitors (PPIs) – drugs that are commonly used to lower stomach acidity – do not increase the risk of hospitalization for Clostridium difficile-associated disease (CDAD) in elderly patients taking antibiotics. CDAD is a common cause of severe diarrhea and can even lead to death.

“Previous research examining the association between PPI use and the risk of CDAD has produced conflicting results, and until now, no study has examined the association between PPI use and the risk of hospitalization for CDAD. This is an important outcome given the recent increased illness and mortality attributable to CDAD,” said Dr. David Juurlink, ICES scientist and study co-author.

In the report, investigators tracked Ontarians 66 years of age and older who were hospitalized for CDAD, within 60 days of receiving outpatient antibiotic therapy. The study focused on patients taking antibiotics because this is the main risk factor for CDAD. Each patient hospitalized for CDAD was randomly matched to control patients who were treated with antibiotics, but not hospitalized for CDAD.

Of the 1,389 cases and 12,303 matched controls, the results showed that patients hospitalized for CDAD following outpatient antibiotic therapy were no more likely than the control group to have been dispensed a prescription for a PPI in the preceding 90 days. There was also no association between hospitalization for CDAD and more remote PPI use.

“Given the widespread use of PPIs, the recent outbreaks of CDAD in North America and Europe, and the public concern surrounding them, our findings have important public health implications,” said Dr. Donna Lowe, lead author of the study and a Drug Utilization Coordinator in the Department of Pharmacy Services at the University Health Network.

“PPIs are among the most commonly prescribed classes of drugs worldwide, and were taken by almost one fourth of older outpatient antibiotic users in our study. So, our findings suggesting that PPIs are not independently associated with hospitalization for CDAD should be reassuring to both patients and healthcare providers alike.”

The study, “Proton pump inhibitors and hospitalization for Clostridium difficile-associated disease: a population-based study”, is in the November 2006 issue of the journal Clinical Infectious Diseases.

Author affiliations: ICES (Drs. Mamdani and Juurlink, and Mr. Kopp); Department of Pharmacy Services, University Health Network (Dr. Lowe); Departments of Health Policy, Management and Evaluation (Drs. Mamdani and Juurlink), Medicine (Dr. Juurlink), Microbiology (Dr. Low), Pediatrics (Dr. Juurlink), Pharmacy (Dr. Mamdani), University of Toronto; Department of Microbiology, University Health Network/Mount Sinai Hospital (Dr. Low); Department of Medicine, Sunnybrook Health Sciences Centre (Dr. Juurlink).

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.


  • Julie Dowdie
  • Media Relations Officer, ICES
  • (416) 480-4780 or cell (416) 432-8143


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