[Low molecular weight heparin-induced hyperkalemia and hyponatremia. Report of one case].

Low molecular weight heparin-induced hyperkalemia is not an uncommon side effect. The development of hyponatremia is well described although it is less common. We report a 72-year-old woman with lumbar metastases who developed hyponatremia and hyperkalemia on the tenth day of hospitalization. Hyponatremia, with limited criteria for syndrome of inappropriate secretion of antidiuretic hormone, did not resolve with vigorous volume restriction. Hyperkalemia without an acid-base disorder or baseline renal failure, did not resolve after losartan was stopped. Enoxaparin-induced hypoaldosteronism was proposed and the drug was discontinued. After four days' persistence of the electrolyte disturbance, dexamethasone was changed to Hydrocortisone, and parameters normalized in 24 hours. The patient remained well until discharge and during outpatient control.