Hepatotoxicity of Mercaptopurine

Abstract
In a study of 49 leukemic patients, jaundice occurred in 16 of 38 who were treated with mercaptopurine (6-mercaptopurine), but only in one of 11 not receiving the drug. In eight patients jaundice cleared up rapidly on cessation of mercaptopurine therapy, and there was a recurrence of jaundice in two who were rechallenged with the drug. Jaundice was frequently accompanied by oral lesions or leukopenia. Toxic effects occurred somewhat more frequently when the usual dose of 2.5 mg/kg per day was exceeded. All patients receiving mercaptopurine, especially those who developed oral lesions or leukopenia, should be observed for evidence of liver injury. The drug should be promptly discontinued at the first sign of hepatic dysfunction.