V WIJERATNE1, S MAY1
1Tamworth Hospital, North Tamworth, Australia
Background: Hypermagnesemia has long been a complication of end stage renal failure. Proton pump inhibitors(PPI) have been associated with reduced serum magnesium concentrations across patient cohorts. Hypomagnesemia has been associated with cardiac arrhythmias, a common cause of mortality amongst patients on dialysis.
Aim: To determine Mg levels of patients currently on haemodialysis and see if patients on proton pump inhibitors had lower serum magnesium levels.
Methods: We examined a cohort of haemodialysis patients in rural NSW to determine the incident rates of serum hypomagnesemia in patients on proton pump inhibitors. Monthly blood results for at a single point in time were analysed along with their use of PPI’s. Clinically significant hypomagnesaemia was defined as serum levels below 0.70 mmol/L.
Results: Twenty seven of the 61 patients on dialysis were on proton pump inhibitors. Six patients were on oral magnesium replacement. When adjusting for clinically relevant hypomagnesaemia, there was evidence that proton pump inhibitor use was associated with clinically relevant hypomagnesaemia (χ² = 5.82, p = 0.016) with 17% of patients on PPI’s reporting low serum magnesium levels compared to 0% of the non-PPI group. The odds ratio of hypomagnesaemia in haemodialysis patients on proton pump inhibitors was 1.211 ( 95% Confidence interval 1.004-1.460).
Conclusion: Proton pump inhibitors were commonly prescribed amongst patients on haemodialysis. The use of proton pump inhibitors in haemodialysis patients is associated with low serum magnesium levels independent of oral replacement. Their use in patients who may be prone to cardiac arrhythmias already, should be evaluated on a case by case basis with discontinuation of the medication if possible. Dialysate composition may need be adjusted to account for lower serum magnesium levels.
Dr Viduranga Wijeratne is a Renal Advanced Trainee in Tamworth Rural Referral Hospital. He completed his BMed MD at UNSW and his basic physicians training at Concord Repatriation General Hospital.