The first choice for drug treatment is prophylthiouracil (PTU), which crosses the placenta in small amounts and at a slow rate. It can block the synthesis of thyroid hormones in the thyroid gland and block the conversion of T4 to T3.

For newly diagnosed patients, start with 400mg/d of prophylthiouracil. Once the condition improves or stabilizes (usually in 4-6 weeks), gradually reduce the dose to 25% of the initial dose. Do not stop the medication abruptly. Refer to the table for general treatment dosages.

During medication, closely monitor changes in the condition, including resting heart rate, pulse pressure, appetite, and levels of free T3 and free T4.