HYPOmagnesemia associated with PPI therapy

The FDA suggests monitoring should be considered before starting PPI therapy and then periodically....
Mahitab Hany, BS Pharm, PGDipClinPharm, PGDipClinNutrition

As a clinical pharmacist, you will hear about proton pump inhibitor-induced hypomagnesemia. PPI therapy has been associated with hypomagnesemia, possibly due to reduced magnesium absorption. Hypomagnesemia has been reported after three months of PPI therapy, but the risk increases after a year. Data is conflicting on whether PPI therapy causes hypomagnesemia. Two meta-analyses concluded there was an association of PPI therapy with hypomagnesemia; however, two others concluded the risk was unclear due to the heterogenicity of included studies.

     National organizations also differ in their recommendations. Recent American Gastroenterology Association best practice recommendations concluded that long-term PPI users do not need to have serum magnesium routinely monitored. The FDA suggests monitoring should be considered before starting PPI therapy and then periodically. The American College of Gastroenterology concludes there is insufficient data to make a meaningful recommendation for monitoring magnesium.

Consider monitoring magnesium in patients also using medications that can lower magnesium levels (e.g., thiazides, loop diuretics) or may be adversely affected by hypomagnesemia (e.g., hypomagnesemia can increase the risk of digoxin toxicity). Consider checking baseline magnesium levels and then periodically during long-term PPI therapy. See our note, "Pharmacotherapy of oral proton pump inhibitors (PPIs)" for more details.

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