Quinidine-induced hepatitis. A common and reversible hypersensitivity reaction.

In a retrospective survey of drug-induced hepatitis during a ten-year period, we found that quinidine sulfate was the most common offending agent. We analyzed the clinical and laboratory data of the 33 cases of quinidine-induced hepatitis and noted the following: (1) It is an easily recognized drug reaction, because, in most patients, fever preceded liver damage. (2) The clinical picture usually includes fever and sometimes is accompanied by gastrointestinal symptoms, rash, and thrombocytopenia, which resolved after discontinuation of drug therapy, but reappeared promptly after a rechallenge. (These features suggest a hypersensitivity mechanism.) (3) The histologic findings of the liver biopsy specimens consisted of portal and parenchymal, acute and chronic hepatitis, combined with granulomas. (4) In a long-term follow-up study of 15 patients, no liver function abnormalities were found. We thus conclude that quinidine-induced hepatitis, when recognized early, is a reversible drug reaction.