OUTCOME OF GRAVES-DISEASE AFTER ANTITHYROID DRUG-TREATMENT IN TAIWAN

The outcome of Graves' disease after treatment with antithyroid drugs (ATDs) varies widely among countries, and large-scale studies in Asia are rare. We investigated the associations of various clinical and lab oratory features with the outcome of ATD therapy for Graves' disease i n Taiwan. A total of 210 patients (177 women, 33 men; mean +/- SD age, 41.7 +/- 15.1 yr) treated with ATD in Taiwan were included. ATD thera py started with methimazole 30 mg daily or propylthiouracil 300 mg dai ly and was continued until a euthyroid state was achieved. Afterwards, 154 patients received a maintenance dose of ATD alone, while 56 patie nts received a combination of an ATD and thyroxine (L-T-4). Patients w ere considered to be in remission if they remained in a euthyroid stat e for more than 2 years after drug withdrawal. The mean follow-up peri ods were 45.0 +/- 20.9 months for patients with remission and 30.4 +/- 19.8 months for those with relapse. Relapse occurred in 126 (60%) pat ients during the follow-up period, within 3 months after drug withdraw al in 47 (37%), and within 6 months in 60 (46%). The relapse rate was 100% among patients with two or more previous relapses. Patients with a second occurrence had a higher relapse rate than those with a first occurrence (84% vs 43%). Past history of reccurrence, goiter size, thy roid-stimulating hormone level and thyrotropin-binding inhibition immu noglobulin activity at the end of ATD treatment were independently ass ociated with relapse. Prolonged duration of treatment did not yield be tter results in patients with larger goiters or a history of recurrenc e, or both. Combination therapy with L-T-4 yielded similar results to those achieved with ATD treatment alone. In conclusion, the relapse ra te of Graves' disease after ATD treatment in Taiwanese patients was hi gh, especially in those with a history of recurrence. The treatment du ration and drug regimen did not affect the outcome.