Endocrine Abstracts

Agranulocytosis complicating carbimazole (CBZ) therapy occurs in <1% of treated patients and generally presents in a charachteristic way. A 72 year old female presented with thyrotoxicosis (FT4 44.9 pmol/l, NR 12.5-20.5), confirmed as Graves disease on investigation. Treatment was commenced with carbimazole. 4 weeks after beginning therapy she complained of a painful red eye, nausea, anorexia and weight loss. Examination confirmed iritis. Subsequent investigations revealed a mixed hepatocellular/obstructive pattern of LFTs, and a low white cell count (Neutrophils 1.1x 10⁹/l, NR 1.5-7.5). No oropharyngeal lesions were seen. Upper abdominal computerised tomography showed an abnormal stomach and omentum. Upper gastrointestinal endoscopy demonstrated a very unusual morphological appearance to the stomach, confirmed on histology as pseudomembranous gastritis. Resolution of biochemical, morphological and radiological features mirrored recovery of bone marrow function following withdrawal of carbimazole and substitution of propylthiouracil. Pseudomembranous gastritis has only rarely been reported before in association with chemotherapy associated agranulocytosis, but never with carbimazole therapy. The combination of abdominal pain, weight loss and abnormal liver function should alert fellow clinicians to the possibility of carbimazole associated bone marrow suppression in the absence of more typical signs.