Low Prevalence of Hypomagnesemia in Long-term Recipients of Proton Pump Inhibitors in a Managed Care Cohort

Background & Aims Chronic intake of proton pump inhibitors (PPI) has been associated with hypomagnesemia, but prevalence of PPI-associated hypomagnesemia is not known. Methods We examined the prevalence of hypomagnesemia among long-term PPI recipients by using a large health maintenance organization database. We collected data on 10,167 participants eligible for chronic drug prescriptions from 2008 through 2013. Adult subjects receiving continuous PPI therapy for ≥6 months between 2008 and 2013 and ≥1 serum magnesium determination(s) were identified. Patients with any magnesium levels less than 1.6 mg/dL were selected for analysis; those with recognizable causes of altered magnesium homeostasis were excluded. Results Five hundred ninety participants received long-term PPIs, and 414 (70.2%) met the inclusion criteria for a total exposure of 2293 PPI-years (average, 5.7 years/subject). Of these patients, 57 (13.8%) had ≥1 low serum magnesium; 5 were no longer on PPIs, and 44 had other recognizable causes for hypomagnesemia (25 receiving diuretics, 8 with chronic diarrhea, 8 with chronic kidney disease, and 3 with malignancies). Of the 8 remaining patients (7 female; mean age, 71.2 ± 13.4 years; mean daily medications, 5.4 ± 1.1), mild hypomagnesemia (range, 1.2–1.5 mg/dL) was noted in 13.9% of 289 measurements. All 8 patients had normal serum levels of magnesium at their final measurement. Conclusions In the absence of known precipitating factors, chronic PPI use does not appear to be associated with hypomagnesemia.