The treatment of hyperthyroidism with methimazole in a pregnant who developed agranulocytosis due to propylthiouracil

The most common cause of hyperthyroidism during pregnancy is Graves' disease. Anti-thyroid drugs are primarily used in the treatment of pregnant women with Graves’ disease. Anti-thyroid drugs’ side effects include itching, jaundice, skin rash, drug fever, arthralgia, lupus-like syndrome, toxic hepatitis, vasculitis, hypergammaglobulinemia, and lymphadenopathy. Although agranulocytosis, a serious side effect of anti-thyroid drugs, is rare, it is difficult to treat when it occurs during pregnancy. In this article, we aimed to present a pregnant case with Graves' disease who developed agranulocytosis after the initiation of propylthiouracil, whose agranulocytosis was treated with granulocyte colony-stimulating factor, and subsequently, hyperthyroidism was treated with methimazole without any problem.