A recent analysis indicates that clinicians should use caution in prescribing acid-suppressive drugs for patients at risk for pneumonia, because use of a proton pump inhibitor (PPI) or histamine2 (H2) receptor antagonist may increase a person’s chances of contracting the illness.

Chun-Sick Eom, MD, MPH, and colleagues sought to clarify the inconsistent findings yielded by previous studies of an association between the use of acid-suppressive drugs and pneumonia risk. Their meta-analysis of eight observational studies showed overall pneumonia risk to be 27% higher among PPI users and 22% higher for people on H2 receptor antagonists. In addition, 23 randomized controlled trials suggested a 22% higher risk of hospital-acquired pneumonia for the users of H2 receptor antagonists.

Based on the widespread use of acid-suppressive medications, Dr. Eom’s research team calculates that 24 or 25 cases of pneumonia can be expected for every 1,000 individuals receiving these agent. “Given that 40% to 70% of patients admitted to the hospital receive acid-suppressive drugs, a considerable burden of morbidity and mortality of hospital-acquired pneumonia may be attributable to this type of therapy,” caution the authors in an online report that appeared in the Canadian Medical Association Journal. “In the context of community-acquired pneumonia, the impact of these drugs could be even more serious.”

Clinicians are advised to consider carefully any decision to prescribe acid-suppressive drugs, especially for patients who are already at risk for pneumonia. “Since it is unnecessary to achieve an achlorhydric state in order to resolve symptoms, we recommend using the optimal effective dose of the drug necessary to achieve desired therapeutic goals,” the investigators stated.