OBJECTIVE: To report the occurrence of hypokalemia in a patient with pheochromocytoma. METHODS: We present a case report and discuss the possible role of hyperepinephrinemia as a cause of hypokalemia. RESULTS: A patient with pheochromocytoma had hypokalemia associated with vomiting, but hypokalemia recurred after repletion of potassium and cessation of vomiting. She had substantially increased epinephrine concentrations in the plasma and in the subsequently excised pheochromocytoma. Because evidence has shown that infusions of epinephrine induce hypokalemia in normal human subjects, the relationship between serum potassium and plasma epinephrine concentrations in 16 previous patients with pheochromocytoma and 4 patients with primary hyperepinephrinemia was studied. A significant negative correlation was noted. CONCLUSION: The presence of hypokalemia and its potential role in predisposing to arrhythmias in patients with pheochromocytoma merit further study.
OBJECTIVE: To report the occurrence of hypokalemia in a patient with pheochromocytoma. METHODS: We present a case report and discuss the possible role of hyperepinephrinemia as a cause of hypokalemia. RESULTS: A patient with pheochromocytoma had hypokalemia associated with vomiting, but hypokalemia recurred after repletion of potassium and cessation of vomiting. She had substantially increased epinephrine concentrations in the plasma and in the subsequently excised pheochromocytoma. Because evidence has shown that infusions of epinephrine induce hypokalemia in normal human subjects, the relationship between serum potassium and plasma epinephrine concentrations in 16 previous patients with pheochromocytoma and 4 patients with primary hyperepinephrinemia was studied. A significant negative correlation was noted. CONCLUSION: The presence of hypokalemia and its potential role in predisposing to arrhythmias in patients with pheochromocytoma merit further study.