Agranulocytosis associated with anti-thyroid drug in patients with Graves' thyrotoxicosis--report of 11 cases.

Retrospective analysis of 11 Chinese patients with Graves' thyrotoxicosis developing agranulocytosis during anti-thyroid treatment was done. Seven of them received methimazole and 4 received carbimazole. None of the 11 patients had taken propylthiouracil. The major chief complaints were high fever (100%), chillness (91%), and sore throat (73%). The duration of drug treatment prior to the detection of agranulocytosis ranged from 13 to 63 days (mean +/- 1SE: 33.1 +/- 16.1). At the time of agranulocytosis detected, the peripheral leukocyte counts were 0.5 to 2.1 X 1000/mm3 (mean +/- 1SE: 1.05 +/- 0.47 X 1000/mm3), absolute neutrophil counts 0 to 450/mm3 (mean +/- 1SE: 54.27 +/- 132.12/mm3), and hemoglobin 8.2 to 15.9 g/dl (mean +/- 1SE: 11.85 +/- 2.24 gm/dl). Three of the 11 patients had positive bacterial blood cultures. The recovery time of absolute neutrophil counts above 500/mm3 ranged from 3 to 25 days (mean +/- 1SE: 10.5 +/- 6.6) after discontinuation of antithyroid drugs. Mortality was found in 2 of them (18%).