Recalcitrant Hyperkalaemia Associated with a Single Dose Administration of Zoledronic Acid for Treatment of Post-Menopausal Osteoporosis

Hyperkalaemia is a very rare complication associated with zoledronic acid. We report the case of a patient with hyperkalaemia recalcitrant to treatment. A 72 year-old woman who was diagnosed with post-menopausal severe osteoporosis following a bone mineral density scan was treated with a single dose of zoledronic acid infusion. After 3 weeks, the patient’s serum potassium level increased from a baseline of 3.8 mmol/L to 5.9 mmol/L. Renal function was normal and all other possible causes of hyperkalaemia were excluded. She was started on oral sodium polystyrene sulfonate 15 g twice daily. Her serum potassium level remained persistently elevated over the next 9 weeks before it finally returned to a normal level on the 13th week after zoledronic acid infusion. We recommend close monitoring and prompt treatment of hyperkalaemia should it occur.