Severe hyperkalemia caused by indomethacin and potassium supplementation.

Treatment with a combination of indomethacin and potassium chloride supplementation resulted in severe hyperkalemia in a patient with Bartter's syndrome. The clinical and electrocardiographic findings and hyperkalemia improved promptly with intravenous administration of sodium bicarbonate, glucose, and insulin, discontinuation of the potassium supplement, and reduction of the indomethacin dose. This case suggests that life-threatening hyperkalemia can occur when indomethacin and potassium supplementation are prescribed simultaneously in Bartter's syndrome.