medwireNews: People taking histamine 2 receptor antagonists (H2RAs) have a nearly 50% increased risk for developing Clostridium difficile infection, report researchers.
Imad Tleyjeh (Mayo Clinic, Rochester, Minnesota, USA) and colleagues say that the acid suppressants should be used with caution in hospitalized patients receiving antibiotics, who had the greatest increase in risk.
The meta-analysis was based on 24 case-control studies and 11 cohort studies reporting community- and hospital-acquired C. difficile infection among a total of 201,834 participants.
H2RA use was associated with a 44% increased risk for C. difficile infection compared with nonuse, an association that remained when only high-quality studies were considered.
The greatest risk for C. difficile infection was among hospitalized patients receiving antibiotics, for whom the number needed to harm (NNH) one patient was 58 treated cases at 2 weeks. Meanwhile, among those not receiving antibiotics the NNH was 425.
Tleyyjeh and colleagues say in PLOS One that it is not known how the drugs might influence C. difficile infection but suggest that decreased gastric acid levels may permit the survival of the vegetative form of the bacterium, which is usually killed by gastric acid.
The US Centers for Disease Control and Prevention has previously issued a warning over the association between the use of proton-pump inhibitors and C. difficile infection. However, the role of H2RAs has not been explored, despite the prevalence of their use, the authors explain.
But they found a very low risk for C. difficile infection among the general population taking H2RAs with a NNH at 1 year of 4549.
"Our findings are re-assuring to the public that H2RAs use in the general population as over-the-counter medications do not pose significant [C. difficile infection] risk," they note.
However, they say that greater care should be given when using the drug in hospital settings.
"Given the relatively low NNH needed to cause a case of [C. difficile infection] in hospitalized patients receiving antibiotics it becomes necessary to judiciously use H2RAs in these patients," they write.
"In addition, reducing the inappropriate use of acid-suppression medications in this patient population could lead to a significant reduction in the incidence of [C. difficile infection]."
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