[Treatment of Basedow disease with synthetic antithyroid drugs. Evaluation of the dose on the efficacy of the long term treatment]

Abstract

A direct immunosuppressive action of antithyroid drugs (ATD) has been suggested by the progressive decrease of thyroid antibodies during treatment. High doses of ATD were then proposed to improve the level of remissions of Graves' disease but the results of such high doses remain a matter of controversies. The french Group of Research on Thyroid (GRT) underwent a multicenter study comparing the efficacy of 60 mg/d of carbimazole with the minimal dose required to obtain euthyroidism in 197 randomly and equally distributed patients. After 18 months of therapy and a 2-year follow-up the remissions are 70.9% with high and 53% with low doses (p = 0.03). After the third year of follow-up, this difference was not significative (p = 0.06). Moreover after a 3-year follow-up the remission rate of high dose (60.3%) is not different from which is obtained with intermediate one (20 to 30 mg/d) associated with a permanent decrease of TSH by thyroid hormone.