A Study of Effect of Metimazole-Levothyroxine Combined Therapy Compared With Metimazole Alone in Prolonged Remission of Graves Disesase

Graves disease is the most prevalent form of thyroxicosis (60-80%), which is caused by an autoimmune reaction. Treating with antithyroid drugs usually lead to prolonged remission in 30%-40% of cases. Paradoxically it is assumed that adding thyroid hormones to the therapy would give more bebefits because of preventing the feedback of TSh to further stimulate the thyroid gland after using antithyroid drug. In this study we compared the effect of adding levothyroxine to the routine therapy in reducing the relapse of thyrotoxicosis.

This was a clinical-trial study in which we compared the two regimens of metimazole plus levothrixine (regimen A), with metimazole alone(regima B), in reducing the graves diseases relapses.

In this 7 years study, 262 patients finished the trial. 137 were assign as group A and 125 cases were assigned to group B. randomely. Graves was most prevalent in 3rd to 5th decades. 52.3% of disease had grade II Goiter. The rate of relapse was 36.4% in group A and 61.6% in group B. during 3 years after discontinuation of therapy.

The peak age of prevalence was found out to be lower than eastern reports (3-5 in comparison to 5-6 decades). Clinical manifestations was not significantly different from other studies. The two regimen results were compared by Or method and calculating Or, in grade I goiter was 0.27 and in grade II was 0.29, grade III was 0.32, which has a meaningful difference and implies regimen A is effective in reducing the prolonged rate of relapse but in garde Iv goiter, there is not significant difference in relapsing in two group.