[Effect of thyroxine upon prevention of recurrence of Graves' disease treated with antithyroid drugs].

OBJECTIVE

To investigate the effect of thyroxine upon the prevention of recurrence of Graves disease after treatment by antithyroid drugs.

METHODS

Sixty patients newly diagnosed as Graves disease were treated with methimazole for 6 months and then randomly distributed into three groups. Patient in group A and group C received small dose of methimazole plus L-T(4) 50 microgram/d, and patients in group B were treated with methimazole in small dose only. Twenty four months later, only L-T(4) 50 microgram/d, without methimazole, was administered to the patients of group A; methimazole in maintenance dose was administered continuously to the patients of group B, and patients in group C were treated with methimazole in maintenance dose plus L-T(4) 50 microgram/d. Such treatments lasted 6 months. Post-treatment follow-up survey was conducted to the three groups.

RESULTS

The titers of thyroid-stimulating Ab (TSAb) in groups A and C were lower than that in group B. However, the recurrence rates among the three groups (4/20, 20%; 4/20, 25%; and 4/20, 20% respectively) were not significantly different.

CONCLUSION

Both treatment of Graves' disease with methimazole plus L-T4 and treatment with prolonged use of methimazole cannot reduce the recurrence rate more effectively than treatment with only methimazole. The level of TSAb is not the only factor that influences the recurrence of Graves disease.