Jaundice related to thyrotoxicosis and not as an effect of antithyroid drugs is a rare complication that usually occurs in the presence of heart failure (HF) or hepatitis. We report a case of a 54-year-old white woman with hyperthyroidism caused by Graves's disease and jaundice despite methimazole suspension. Bilirubin fluctuated at high values, between 30.0 and 52.3 mg/dL, transaminases were slightly increased, on admission ALT = 46 U/L and AST = 87 U/L; coagulation indices and serum proteins were on the lower limit of the normal range with PT 68% and albumin = 2.5 g/dL. Serology for hepatitis was negative. After the first radioiodine therapy (RT), bilirubin reached its maximum, which coincided with the worst period of HF exacerbation. Bilirubin normalized 4 weeks after the second RT, with the stabilization of HF and normalization of thyroid hormones. We discuss the possible etiologies of severe jaundice in hyperthyroid patients, as well as the difficult anticoagulant therapy with warfarin.
