Single daily dose short term carbimazole therapy for hyperthyroid Graves' disease

Twenty-one patients with hyperthyroid Graves' disease were treated with carbimazole 30 mg daily, given as a single dose. Propranolol was also given for the first 3 weeks. All became clinically euthyroid with normal serum thyroxine (T4) levels, usually within 1-3 months. Patients with large goitres and raised serum alkaline phosphatase concentrations took longer to respond. In 19 patients a positive thyroid stimulating hormone (TSH) response to intravenous thyrotrophin releasing hormone (TRH) developed. Carbimazole was stopped soon after (median time of treatment 18 weeks, range 9-41 weeks) and 18 patients have been followed. Seven of these (39%) have remained in remission from hyperthyroidism for more than one year (median 77 weeks). Carbimazole 30 mg once daily is a convenient and effective treatment for hyperthyroid Graves' disease. Many patients will achieve prolonged remissions if treatment is stopped when serum T3 and T4 levels are in the low-normal range, usually 2-4 months after clinical euthyroidism has been reached.