Proton Pump Inhibitors Can Impact Magnesium Levels, Study FindsJul 12, 2011 | Parker Waichman LLP
A new study is backing up the U.S. Food & Drug Administration's (FDA) recent decision to issue a warning about low magnesium levels and proton pump inhibitors. The study, which was reported at the annual Digestive Disease Week conference in May, found that used of the popular heartburn drugs was associated with an increased risk of hypomagnesemia occurrence, which remained significant after adjustment for all confounders.
Hypomagnesemia - low serum magnesium levels - is a very serious condition, that if not treated can lead to muscle spasm, irregular heartbeat and convulsions. The FDA issued an alert on hypomagnesemia in March, after a review had uncovered 38 cases of hypomagnesemia among proton pump inhibitors in the Adverse Event Reporting System, and 23 other cases in the literature. At the time, the agency recommended that healthcare providers consider obtaining serum magnesium levels before their patients begin treatment with prescription proto pump inhibitors. The agency said they should also consider periodic testing if patients are also being treated with medications such as digoxin, diuretics or drugs that may cause hypomagnesemia.
This new study, presented by Dr. Jen-Tzer Gau chair of geriatric medicine/gerontology at Ohio University College of Osteopathic Medicine, involved 1,317 patients at a rural community hospital in southeast Ohio. Of those, 464 used proton pump inhibitors, while 853 did not. Upon admission, the mean magnesium level 1.91 mg/dL among proton pump inhibitor users, compared with 2.00 mg/dL among nonusers. Upon analysis, the odds ratio was for hypomagnesemia among users of the drugs versus non users was 2.29 after adjustment for age, sex, and serum albumin levels . The ration was 2.21 after researchers also adjusted for serum levels of potassium, calcium, and creatinine; supplementation with potassium and magnesium; history of diabetes and chronic obstructive pulmonary disease; and diuretic use, Dr. Gau said.
In addition to those factors, the fully adjusted model also accounted for other variables, including history of heart failure and coronary artery disease, a diagnosis of acute gastrointestinal illness, and use of iron supplements, antipsychotics, antihistamines, narcotics, NSAIDs, antidepressants, beta2-agonist bronchodilators, inhaled corticosteroids, and oral laxatives.
Dr. Gau did note that the study had its limitation, including a lack of data on duration of proton pump inhibitor use, though it is likely that most patients were long-term users.
In its March alert, the FDA did say that its review revealed that most cases of hypomagnesemia among proton pump inhibitor users had taken the drugs for more than one year, though there were cases reported in people who had used the medications for at least three months.