Carbimazole-Induced Hepatotoxicity - Avoid Rechallenging

Abstract

All thioamide anti - thyroid medications are known to be associated with liver dysfunction. Cholestasis is most commonly reported in association with carbimazole/methimazole. We report a patient with Graves’ disease, who developed acute Hepatocellular dysfunction associated with carbimazole. There is limited data available on re -exposure in this situation. The patient rechallenged herself twice and subsequent exposures resulted in an increasingly shorter time to symptom onset until finally even a single 5mg tablet rapidly provoked severe symptoms and abnormal liver function tests. This case supports the need to avoid anti - thyroid medication rechallenge in patients who develop significant liver dysfunction following their use and identifies that carbimazole may be associated with acute Hepatocellular dysfunction and not just Cholestasis.