History: A 72-year-old woman was admitted because of severe acute tetraparesis, more marked proximally. For six months she had been taking ibuprofen, up to 4800 mg daily, for a painful ulcer of the lower leg.
Investigations: Biochemical tests revealed marked hypokalaemia (serum potassium 1.4 mmol/l) with a metabolic acidosis (pH 7.29). The ECG showed changes of hypokalaemia (ST-segment depression and U wave).
Treatment and course: Within two days of administering potassium and bicarbonate the pareses completely regressed. Transitorily abnormal renal functions also rapidly normalized after ibuprofen had been discontinued.
Conclusion: The biochemical findings suggest renal tubular acidosis, type 2, most likely caused by the excess intake of ibuprofen, a drug which can cause renal dysfunctions with life-threatening electrolyte abnormalities.