The effect of the combination therapy with antithyroid drug and thyroxine in Graves' disease / 대한내과학회지

ABSTRACT

OBJECTIVES: It was recently reported that the administration of T4 during antithyroid drug(ATD) therapy resulted in a significant decrease of antibodies to TSH receptors as well as the rate of recurrence of active Graves' disease following discontinuance of ATD treatment. But, there is still controversy whether combination therapy is efficient. Therefore, the present study was undertaken to evaluate the effect of T4 administration of patient with Graves' disease who were being treated with ATD. METHODS: We studied 56 patients received methimazole(MMI) alone(Group 1) and 48 patients received methimazole plus T4(Group 2), They are diagnosed active Graves' disease at department of internal medicine, Kwang ju Christian Hospital from January, 1994 to December, 1995. All the patients were treated initially with 30mg of methimazole daily for one month after then, in the Group 1(methimazole alone), the dose of methimazole was adjusted as necessary to achieve normal serum concentrations of T3, T4, and TSH. The patients of Group 2(methimazole plus T4) continue to receive the combination of T4 at a dose of 100 microgram daily. Simultaneously, we estimated the serum concentration of T3, T4, TSH and Thyroid-stimulating immunoglobulin(TSI) antibody at every three months. RESULTS: We obtained the following result. In the group 1, mean TSI values were 50.1%(first visit), 30.6%(6months), and 24.7%(1year). And, in the group 2 mean TSI values were 51.8%(first visit), 33.6%(6months), and 22.7% (1year). After 6 months of discontinuing of therapy, the recurrence rate was no significant difference in the two groups (the recurrence rate were 55.4%, 50.0%, respectively P>0.05). CONCLUSION: These results suggest that T4 administration in combination with MMI therapy have no significant effect in a decrease in levels of TSH receptors antibodies and recurrence rate within 6 months discontinuing MMI therapy as compared with MMI treatment alone.