Cholestatic hepatitis due to methimazole

Abstract

A 32-year-old female patient with hyperthyroidism received methimazole 10 mg orally thrice daily. Three weeks later, she developed fatigue, anorexia, deep-colored urine, and pruritus of whole body skin. Methimazole was stopped. Laboratory tests showed the total bilirubin (TBil) of 463.1 μmol/L, bilirubin direct (DBil) of 348.9 μmol/L, alanine aminotransferase (ALT) of 142 U/L, aspartate aminotransferase (AST) of 64 U/L, and alkaline phosphatase (ALP) of 499 U/L. Cholestatic hepatitis induced by methimazole was considered. The patient received IV infusion of reduced glutathione, polyene phosphatidylcholine, hepatocyte growth-promoting factors, alprostadil, adenosylmethionine 1, 4-butanedisulfonate, and methylprednisolone sodium succinate, and oral ursodeoxycholic acid capsules. Thirteen days later, the laboratory tests showed TBil of 432.3 μmol/L, DBil of 260.6 μmol/L, and total bile acid (TBA) of 564.0 μmol/L. The patient received 4 times of plasmapheresis within 8 days because her pruritus was not improved. On day 3 after the last plasmapheresis, laboratory tests showed TBil of 271.3 μmol/L, DBil of 175.3 μmol/L, and TBA of 483.0 μmol/L. Liver-protective drugs and medications used to treat jaundice were continued. On day 47 after the last plasmapheresis, laboratory tests showed TBil of 22.4 μmol/L, DBil of 8.3 μmol/L, ALT of 35 U/L, AST of 20 U/L, ALP of 114 U/L, and TBA of 47.0 μmol/L. On day 51 after the last plasmapheresis, her pruritus and yellowish skin and sclera disappeared, her urine color returned to normal, and her physical strength recovered. Key words: Methimazole; Chemical and drug induced injury