Primary aldosteronism associated with severe rhabdomyolysis due to profound hypokalemia

A 55-year-old Japanese man was admitted to our hospital with severe weakness. Without measurement of serum electrolyte concentrations, diuretic therapy for hypertension was started 2 weeks prior to admission. Laboratory findings showed profound hypokalemia (1.4 mEq/L), and extreme elevation of the serum creatinine phosphokinase levels (15,760 IU/L), suggesting that the patient had hypokalemic paralysis and hypokalemia-induced rhabdomyolysis. Further evaluations, including adrenal venous sampling strongly suggested that he had primary aldosteronism. He was treated successfully by laparoscopic adrenalectomy. This case provides an important lesson that serum electrolyte concentrations should be measured in hypertensive patients before the administration of antihypertensive agents.