Proton pump inhibitors (antacid drugs) can cause severe magnesium deficiency

Readers here are likely to know that magnesium is necessary for more than two hundred enzymes involved in cell metabolism including the production of ATP (the cellular 'energy currency'). It is less well known that long term use of proton pump inhibitors (PPIs, such as omeprazole, aka Prilosec; Prevacid, Nexium, Protonix, etc.) can cause severe magnesium deficiencies. The authors of a study published in the journal Clinical Endocrinology set out to...

"...explore the mechanism underlying severe hypomagnesaemia in long-term users of proton-pump inhibitors (PPIs)."

One of the most common symptoms of suboptimal magnesium is muscle spasms or cramps. In the subjects they examined, the deficiency was so severe that they were having hypocalcemic seizures (calcium utilization also depends on magnesium). What did they find?

"Both patients were severely magnesium-depleted and had avid renal magnesium retention, implicating a failure of intestinal magnesium absorption...The hypomagnesaemia could be partially corrected by high dose oral magnesium supplementation, and resolved on withdrawal of PPIs."

In other words, the kidneys were trying their best to compensate for the failure of intestinal absorption due to the PPIs but it wasn't enough. Clinicians and any individuals taking PPIs long-term should bear in mind the authors' conclusions:

"PPI use can inhibit active magnesium transport in the intestine...Long-term PPI users who are highly adherent to treatment can eventually deplete total body magnesium stores and present with severe complications of hypomagnesaemia."

There are often more physiological therapies effective for conditions such as gastroesophageal reflux disease (GERD) for which PPIs are commonly prescribed.