Treatment of antithyroid drug-induced agranulocytosis by granulocyte colony-stimulating factor: A case of primum non nocere

A 48-year-old woman who was treated for thyrotoxicosis with methimazole developed agranulocytosis. The methimazole was stopped and treatment with subcutaneous granulocyte colony-stimulating factor (G-CSF) was initiated. Administration of the drug for 8 days did not effectively shorten the recovery period compared with the average reported in the literature without the drug, and may have triggered additional iatrogenic complications. A search of the literature yielded 15 instances of severe antithyroid-drug- induced granulocytopenia (ATDIA) (granulocyte count of less than 0.1 x 10⁹/L) treated with G-CSF. Of the 16 patients, including the 1 reported here, only 3 displayed significant shortening of the agranulocytic period after treatment. We conclude that routine therapeutic application of G-CSF in afebrile severe ATDIG is not justified, and in some cases may generate a cascade of iatrogenic adverse events.