RESUMEN
Acetazolamide (ACZ) is a sulfonamide derivative that inhibits carbonic anhydrase and is the mainstay for prevention and treatment of acute mountain sickness (AMS). Acute kidney injury (AKI) is not well recognized as a complication of ACZ ingestion, especially when low doses are used for short periods of time. We report a case of a healthy, middle-aged man who developed severe AKI after the ingestion of ACZ for AMS prophylaxis. The patient presented with bilateral flank pain and anuric AKI without radiographic signs of obstructive uropathy. All blood and urine testing to determine the cause of AKI were negative or normal. The patient required 2 sessions of hemodialysis due to worsening metabolic derangements, which included severe anion gap metabolic acidosis and hyperphosphatemia. Renal function returned to baseline after 96 hours of supportive care. The pathogenesis of AKI in our patient was attributed to ACZ-induced sulfonamide crystalluria causing intratubular obstruction and retrograde urine flow, but not intraureteric precipitation or obstructive uropathy. This classic presentation of anuric AKI and renal colic has been previously described with higher doses of ACZ for prolonged periods of time but never with low doses for AMS prophylaxis such as in our patient (total dose of 1250 mg within 48 hours). Our case highlights the risk of adverse renal outcomes following ACZ ingestion, even in previously healthy individuals, and suggests that increased fluid intake may be advisable for travelers taking ACZ prophylaxis.