Patients on proton pump inhibitors may eventually suffer from low serum magnesium if taken for long enough, says the Food and Drug Administration, USA. Hypomagnesemia (low serum magnesium) can occur if taken for over one year. The FDA added that in its review, about one quarter of cases did not improve with magnesium supplementation alone – PPI (proton pump inhibitor) treatment had to stop.

Proton pump inhibitors are agents that block the transport of hydrogen iron into the stomach – they are useful in treating gastric hyperactivity. In other words, PPIs reduce stomach-acid levels. They are prescribed for stomach/intestinal conditions, such as GERD (gastroesophageal reflux disease), inflammation of the esophagus, and stomach/small intestine ulcers.

About twenty-one million patients filled PPI prescriptions in the USA in 2009 at outpatient retail pharmacies. Most people are on PPIs for about 6 months.

The following are examples of prescription PPIs:

  • AcipHex (rabeprazole sodium)
  • Dexilant (dexlansoprazole)
  • Nexium (esomeprazole magnesium)
  • Prevacid (lansoprazole)
  • Prilosec (omeprazole)
  • Protonix (pantoprazole sodium)
  • Vimovo (combination of esomeprazole magnesium & naproxen)
  • Zegerid (omeprazole & sodium bicarbonate)

PPIs that can be bought OTC (over-the-counter, no prescription required) include Prilosec OTC omeprazole, Prevacid 24HR (lansoprazole), and Zegerid OTC (omeprazole & sodium bicarbonate).

OTC versions of PPIs have a lower dose than prescription ones and are meant to be used for much shorter periods, perhaps for a couple of weeks up to three times a year. The FDA does not believe OTC PPI treatment has a hypomagnesemia risk if the patient follows the instructions on the label.

Patients with low serum magnesium may experience tetany (muscle spasm), arrhythmias (irregular heartbeat) and seizures (convulsions, fits). Some, however, will have no apparent symptoms. Hypomagnesemia is treated with supplements. Some patients on PPIs who have hypomagnesaemia may have to stop taking the medication.

In a communiqué, the FDA advises doctors to consider obtaining serum magnesium levels before starting a patient on long-term PPI treatment, as well as those taking PPIs with digoxin, diuretics and other medications which may lower magnesium levels.

Digoxin is a medication for the heart. Low magnesium for such patients may have serious side effects. Doctors should consider checking magnesium levels periodically.

The FDA adds that warnings will be included in all labels for prescription PPIs regarding the risk of hypomagnesaemia.

Source: Food and Drug Administration

Written by Christian Nordqvist