Follow-up comparison of short-term versus 1-year antithyroid drug therapy for the thyrotoxicosis of Graves' disease.

We have treated 68 thyrotoxic patients with Graves' disease with a single daily dose of 30 mg methimazole until they were clinically euthyroid and their plasma thyroid hormone concentrations were within normal limits. Sixteen of 56 patients (29%) treated 4.8 +/- 0.2 months (mean +/- SEM; range, 1.5-8.5 for their initial attack of thyrotoxicosis have remained in remission for 54.4 +/- 7.7 months (range, 12-105). Twenty-seven of the patients who relapsed were treated with a subsequent 1-yr course of methimazole. Five of these patients (19%) have maintained a remission for 29.6 +/- 10.8 months (range, 3-66); the remainder relapsed after 7.1 +/- 2.3 months (range, 1-50). If the patients lost to follow-up while known to still be in remission are excluded, the sustained remission rate is 12 of 52 (23%) for initial short term therapy and 3 of 25 (12%) for the subsequent 1-yr of antithyroid treatment. The results of short term antithyroid drug treatment in 12 patients previously treated with long term antithyroid drugs or thyroidectomy were similar, but the follow-up period was not as long. Short term antithyroid drug therapy is a potentially long lasting, innocuous, and relatively inexpensive program for the treatment of Graves' disease, especially for patients with small goiters.