Thyroid Research Thyroid Research Archive Hyperthyroidism

Prolonged low-dose antithyroid drug therapy results in a high remission rate in Graves' hyperthyroidism

(November 2003)

The background of the study. Some patients with hyperthyroidism caused by Graves' disease who are treated with an antithyroid drug remain well after treatment is stopped; they are said to be in remission. This study was done to determine if prolonged treatment with a low dose of antithyroid drug resulted in a high rate of remission.

How the study was done. The study subjects were 44 women and 13 men with hyperthyroidism caused by Graves' disease. They were treated initially with moderate doses of methimazole or propylthiouracil. The doses were reduced gradually as the patients improved. Those patients who remained well were treated with a very low dose of antithyroid drug (5 mg of methimazole or 50 mg of propylthiouracil) every other day for six months. Treatment was then stopped, and the patients were evaluated periodically for two years.

The results of the study. Among the 57 patients who completed the antithyroid drug treatment program, 46 (81 percent) remained well and 11 (19 percent) had recurrent hyperthyroidism during the two-year follow-up period. The recurrence occurred within eight months in 9 of the 11 patients (82 percent).

The conclusions of the study. Prolonged treatment with a low dose of antithyroid drug is associated with a high rate of persistent remission in patients with hyperthyroidism caused by Graves' disease.

The original article. Kashiwai T, Hidaka Y, Takano T, Tatsumi K, Izumi Y, Shimaoka Y, Tada H, Takeoka K, Amino N. Practical treatment with minimum maintenance dose of anti-thyroid drugs for prediction of remission in Graves' disease. Endocr J 2003;50:45-9.