Hypermagnesemia-induced fatality following epsom salt gargles

Hypermagnesemia is a rare cause of coma in a patient with normal renal function. When present, it is often because of iatrogenic medication overdose. We report a fatal case of chronic Epsom salt gargles for halitosis that produced a serum magnesium of 23.6 mg/dL (9.8 mmol/L) and resulted in coma. We review the wide presentation of hypermagnesemia from subtle neurologic and cardiovascular signs to the major life-threatening clinical manifestations of shock, dysrhythmias, coma, and cardiopulmonary arrest despite emergency dialysis.