[Evaluation of the medical treatment of Graves' disease (GD)].

The treatment of Graves' disease (GD) with antithyroid drugs (ATD) leads to remission of the disease in approximately half of patients treated for at least six months, and the overall relapse rate is high, ranging from 60% to 80%. The presence of prognostic features for achieving a remission after medical treatment is a matter of discussion in the literature. The aim of this study is to evaluate the effect of different ATD regimens available in Brazil (propylthiouracil--PTU and methimazole--MMI) on remission and relapse rates of GD, as well as to determine possible predictors of remission and relapse of the disease and the side effects profile. We reviewed the records from all patients submitted to medical treatment of GD (and with no report of prior treatment of the disease) for at least six months and followed for at least 12 months after the drug withdrawal at Hospital Universitário Clementino Fraga Filho (HUCFF), between October 1978 and August 2003. We identified 127 patients, with the age ranging from 18 to 88 years (mean 39.3 +/- 12.8). Remission was observed in 58 patients (45.7%) and relapse occurred in 31 (53.4%), at a mean period of 14.5 +/- 16.1 months. We verified that the duration of symptoms before the beginning of medical treatment, age and gender did not influence the rate of remission and the relapse risk, whereas the presence of large goiter size (> 40 grams), Graves' ophthalmopathy and use of high daily doses of ATD (> or = 600 mg of propylthiouracil/60 mg of methimazole MMI) were associated with a decreased remission rate. Moreover, patients who presented a TSH measurement < 0.4 microIU/mL between 4 to 5 weeks after the drug withdrawal showed an increased relapse cumulative probability. In conclusion, our results confirms that lasting remission rate of GD treated with ATD is relatively low. We concluded that the combination of goiter size > 40 g, ophthalmopathy, and use of daily doses of PTU > or = 600 mg or MMI > or = 60 mg was vigorously related to lack of remission of GD. Furthermore, TSH measurement between 4 to 5 weeks after the drug withdrawal seems to be a useful tool to determine the remission chance and the relapse risk of the disease.