Proton Pump Inhibitors and Severe Hypomagnesaemia

Tim Cundy; Jonathan Mackay


Curr Opin Gastroenterol. 2011;27(2):180-185. 

In This Article


The emergency treatment of patients with symptomatic hypomagnesaemia should be with intravenous magnesium. In an adult with adequate renal function, a typical regimen would be 12 mmol magnesium (given in the form of magnesium sulphate in isotonic saline) infused over 3–4 h followed by a further 12 mmol infused over the following 12 h.

The most important step is to stop the PPI, substituting with a histamine 2 receptor antagonist such as ranitidine or cimetidine. After PPI therapy is discontinued, serum magnesium returns to normal within 1–2 weeks.[15,17•] These patients feel very unwell when hypomagnesaemic and the improvement in their well being is striking. In patients who wish to continue PPIs because their gastric symptoms are not adequately controlled on histamine 2 receptor antagonists, oral magnesium supplements can raise plasma magnesium sufficiently to alleviate the acute symptoms. However, the high doses required can cause diarrhoea, so this is not an attractive option. Anecdotally, we have patients who take PPIs on 2 days a week and histamine 2 receptor antagonists 5 days a week who have mild, asymptomatic, hypomagnesaemia and tolerable control of their gastric symptoms. There is a suggestion that hypomagnesaemia might not be as severe with pantoprazole, the least potent PPI.[17•]