Discontinuing Methimazole

Key Considerations for Discontinuation

The American Academy of Family Physicians recommends standard treatment duration for Graves' disease is typically 12-18 months before considering discontinuation 1, 2
Close thyroid function monitoring is essential after methimazole discontinuation, with regular checks of TSH and FT4, especially during the first year after stopping the medication 1, 2, 3
The American Academy of Family Physicians suggests that definitive treatment options, such as radioactive iodine (I-131) therapy or thyroidectomy, should be considered if discontinuation is not appropriate 1, 4

Methimazole is contraindicated in the first trimester of pregnancy due to potential teratogenic effects, and propylthiouracil is preferred during this period 5
Untreated maternal hyperthyroidism increases risks of preeclampsia, low birth weight, and other complications 1, 2

The American Academy of Family Physicians recommends monitoring thyroid function every 1-3 months for the first year after discontinuation, and being vigilant for signs of recurrent hyperthyroidism 1, 2, 3