Salicylism and glaucoma: mutual toxicity enhancement of acetazolamide and acetylsalicylic acid

We report a case of salicylism caused by association of acetylsalicylic aci d (ASA) and acetazolamide. A 50-year-old woman without chronic renal insuff iciency, was admitted for confusion, cerebellar ataxia associated with hype rchloremic acidosis. She was treated with acetazolamide for simple glaucoma and since 14 days with ASA for acute pericarditis. Clinical features evoke d salicylism despite low serum salicylate level : 178 mg/l. The carbonic an hydrase inhibitor explained the biochemical pattern. Acetazolamide-induced acidosis enhances the non ionized form of salicylate which crosses the biol ogical membrane more rapidly and better than the ionized form. The tissular tropism of non ionized salicylate increases and cerebral toxicity may occu r with low serum level of ASA. ASA also enhances the free form of acetazola mide.