A 63-year-old, hypertensive, nondiabetic man with a 4-year history of gout was hospitalized because of painful swelling of his right foot. His blood pressure had been treated with nifedipine, 20 mg orally, three times daily. On admission, the patient was normotensive (blood pressure, 140/85 mm Hg) and had no clinical signs of congestive heart failure or volume depletion. Physical examination revealed erythema and soft-tissue swelling of the dorsum of the right foot with metatarsal tenderness. Laboratory data showed mild azotemia with a BUN level of 23 mg/dl; serum creatinine, 1.8 mg/dl; creatinine clearance, 70 mllmin; serum potassium, 4.1 mEq/liter; serum bicarbonate, 24 mmol/liter; and serum uric acid, 13.2 mg/dl. Roentgenographic findings were consistent with erosive gout, and a diagnosis of acute gouty attack was made. Indomethacin, 50 mg orally three times daily, was begun. The patient's symptoms improved rapidly, but within 4 days, the BUN rose to 51 mg/dl; serum creatinine, 2.4 mg/dl; serum potassium, 6.6 mEq/liter; and serum bicarbonate, 27 mmollliter; the creatinine clearance decreased to 36 mI/mm, with a fractional excretion of sodium of 0.06% and a urinary potassium concentration of 21 mEq/liter. The urinary sediment was unremarkable. The patient's blood pressure ranged from 140/85 to 150/90 mm Hg and no major changes in urinary output were noted. Indomethacin treatment was discontinued and replaced by colchicine. The patient's renal function and serum potassium level returned to baseline values within 4 days.