Thyroid Research Thyroid Research Archive Hyperthyroidism

Thyroxine therapy does not alter outcome in patients with hyperthyroidism due to Graves' disease

(March 2003)

The background of the study. Combined antithyroid drug and thyroxine (T4) therapy does not result in a higher rate of prolonged remission in patients with hyperthyroidism caused by Graves' disease than does therapy with an antithyroid drug alone. This study evaluated whether T4 therapy given after successful antithyroid drug therapy might increase the rate of prolonged remission.

How the study was done. The study subjects were 332 patients (284 women, 48 men; mean age, 42 years) with hyperthyroidism caused by Graves' disease. The patients were treated with an antithyroid drug for 12 to 15 months, and had to be normal during the last six months of therapy. Therapy then was discontinued. One month later, the 225 patients (68 percent) who were euthyroid and had a normal serum thyrotropin concentration were randomly assigned to receive T4 or no therapy. Most of the other 107 patients again had hyperthyroidism at this time. The 225 patients randomly assigned to receive T4 or no therapy were evaluated periodically for two years.

The results of the study. The frequency of recurrent overt hyperthyroidism in the T4-therapy group was 18 percent in one year and 24 percent in two years, as compared with 20 percent in one year and 32 percent in two years in the no-T4-therapy group (differences not statistically significant).

The conclusions of the study. Among patients with Graves' hyperthyroidism T4 therapy after antithyroid drug therapy does not reduce the frequency of recurrent hyperthyroidism

The original article. Hoermann R, Quadbeck B, Roggenbuck U, Szabolcs I, Pfeilschifter J, Meng W, Reschke K, Hackenberg K, Dettmann J, Prehn B, Hirche H, Mann K. Relapse of Graves' disease after successful outcome of antithyroid drug therapy: results of a prospective randomized study on the use of levothyroxine. Thyroid 2002;12:1119-28.