Study finds increased risk of B12 deficiency among long-term users of PPIs, H2RAs.

The New York Times (12/10, Saint Louis) reports on a study published in the Journal of the American Medical Association and conducted by researchers at Kaiser Permanente finding that proton-pump inhibitors and histamine 2 receptor antagonists “increase the risk of vitamin B12 deficiency.” That applies particularly to those patients who use the medications for two years or more. The study’s senior author Dr. Douglas A. Corley commented, “This raises the question of whether people taking these medications for long periods should be screened for vitamin B12 deficiency.” The study was based on the medical records of 25,956 adults diagnosed with vitamin B12 deficiency and 184,199 patients who did not have B12 deficiency during the period 1997-2011. Specifically, those “who took P.P.I’s for more than two years were 65 percent more likely to have a vitamin B12 deficiency” as 12 percent of those with B12 deficiency “had used P.P.I.’s for two years or more,” compared to “7.2 percent of control patients,” while 4.2 percent were “long-term” users of H2RA’s compared to “3.2 percent of nonusers.”

        The San Francisco Chronicle (12/11, Colliver) explains that B-12 deficiency is associated with greater “risk of dementia, nerve damage, anemia and other potentially serious medical problems.” Dr. Corley also pointed out that PPIs have been connected to “increased risk in food-borne infections and bone fractures” in earlier research “because these drugs make it difficult to absorb certain nutrients.” In response to the study, Dr. Keith Obstein, a gastroenterologist at Vanderbilt University Medical Center in Nashville and a committee member of the American College of Gastroenterology, said that “the study gives physicians another potential side effect to discuss with their patients.”

        Reuters (12/11, Seaman) reports that Dr. Corley said that those taking the medications should not simply stop, but that they “should have their B12 levels checked.” He also said that patients should take the smallest effective dose and for as little duration as possible. Reuters lists a number of PPIs omeprazole, esomeprazole, and lansoprazole, and H2RAs cimetidine, famotidine, and ranitidine.

        BBC News (12/11) reports that Prof Mark Pritchard of the British Society of Gastroenterology pointed out that “only a minority of patients” who were long-term users of the medications were also B12 deficient. The report found that higher doses led to greater likelihood of deficiency, and the link “was stronger in women and younger age groups,” but it also found that “the overall risk was still low.”

        HealthDay (12/11, Gordon) reports that last year, there were over “150 million prescriptions” for PPIs, while lower doses are available over the counter.

        MedPage Today (12/11, Petrochko) reports the population of those with B12 deficiency was “mostly female (57.4%), 60 or older (67.2%), and were white (68.4%).”

        NPR (12/11, Shute) also covered the study in its “Shots” blog.