Do higher doses of carbimazole improve remission in Graves' disease ?

The aim of this study was to determine whether a course of carbimazole therapy in higher than normal doses could improve remission rates in Graves' disease, 77 patients were randomly allocated to one of two treatment groups. Group 1 ( n = 33) received a 12-month course of 60 mg/day carbimazole. Group 2 ( n = 44) received 45 mg/day for the first month, 30 mg/day for the second month, and 20 mg/day for the remaining 10 months. All patients were started on T3 between 2 and 4 months after commencing therapy, to maintain euthyroidism. After carbimazole/T3 therapy was withdrawn, patients were followed for either 12 months or until they relapsed. A total of 14 patients (five Group 1, nine Group 2) were withdrawn from the study. There was no significant difference in mean thyroid hormone levels between the two treatment groups during treatment. TT4 concentrations fell significantly faster during the first 4 weeks of treatment in Group 1 patients. Of the 63 patients who completed the study, 30 relapsed and 33 remained in remission. Of those who relapsed, 10 (33%) were from Group 1 and 20 (67%) from Group 2. Of those in remission, 18 (54%) were from Group 1 and 15 (45%) from Group 2. High doses of carbimazole were associated with few adverse side-effects and an improved remission rate.