Endocrine Abstracts

Grave’s disease is an auto-immune disorder which responds well to medication and up to half of the patients who take anti-thyroid drugs go into remission. We present a patient with Graves’ disease, who developed acute hepatitis associated with Carbimazole and, re-challenged with Carbimazole when she represented with in fast atrial fibrillation (AF) with relapse of hepatitis. A 75 year-old lady admitted with palpitation and chest tightness. She had a background of paroxysmal AF. She was found to be in AF with fast ventricular response and blood tests done during her admission showed abnormal thyroid function tests (TFT) consistent with hyperthyroidism: TSH <0.01 mU/l (0.3-5.0), FT4: 33.5 pmol/l (7.9-16.0), FT3: 11.7 pmol/l (3.8-6.0), TSH receptor antibody 5.5 IU/l (0-0.9). Patient was started on Carbimazole 20 mg once a day and planned for follow up as outpatient with the endocrine team within 2 months. Few weeks after discharge, she presented with chest tightness and blood tests revealed deranged liver function tests (LFT); total bilirubin 29 umol/l (0-21), ALT 295 U/l (<35) and ALP 458 U/l (30-130). Carbimazole was discontinued. She has had a normal liver ultrasound as well as normal autoimmune and viral hepatitis screen. Her LFT improved after stopping Carbimazole. She was followed up by the endocrine team post-discharge and definitive treatment in the form of total thyroidectomy was planned. Patient was re-admitted three weeks post outpatient follow up due to palpitations and fast AF. Patient refused to try Propylthiouracil and hence she was restarted on low dose of carbimazole with strict weekly LFT follow up until thyroidectomy could be arranged. However, while trialed on Carbimazole, LFTs started getting deranged (ALT raised to 64 U/l from 29 U/l) and Carbimazole was again discontinued. Two weeks following discontinuation of Carbimazole LFT returned to normal: total bilirubin 8 umol/l, ALT 24 U/l and ALP 125 U/l. Patient’s condition discussed with surgical team and her total thyroidectomy appointment was expedited. She was started on Lugol’s iodine 10 days prior to surgery with normalization of TFT. Patient underwent total thyroidectomy which was uneventful. Hepatotoxicity is rare but serious side effect of thyrostatic medications. The drug should be withdrawn immediately and alternative therapy for thyrotoxicosis should be considered. This case strongly supports the need to avoid antithyroid drugs (ATD) rechallenge in patients who develop significant liver dysfunction following ATD use and identifies that Carbimazole may be associated with acute hepatocellular dysfunction and not just Cholestasis.