Acetazolamide and symptomatic metabolic acidosis in mild renal failure.

Acetazolamide is widely used to treat glaucoma because it reduces the rate of formation of aqueous humour.1 It should be remembered, however, that acetazolamide inhibits carbonic anhydrase in the renal proximal tubular epithelium, which results in a bicarbonate diuresis. Indeed, acetazolamide was first introduced to treat glaucoma because of this diuretic action.2 We report on two patients in whom acetazolamide induced a symptomatic metabolic acidosis. Both patients were elderly and had mild renal impairment.