Short-term effects of combined treatment with potassium bromide and methimazole in patients with Graves’ disease

Abstract

Background: Potassium bromide is used as a sedative and an anti-epileptic drug for children and adolescents. Rodent animal studies have shown that bromide ions inhibit thyroid hormone synthesis by decreasing the iodine concentration in thyroid tissue. Aim: To observe the short-term clinical effects of combined treatment with potassium bromide and methimazole in patients with Graves’ disease. Materials and methods: Sixty patients with Graves’ diseases were randomized in groups. Thirty patients in the combined treatment group were treated with methimazole (10 mg, tid) and potassium bromide (1 g, tid); 30 patients in the methimazole only group were treated with methimazole (10 mg, tid) and starch placebo (1 g, tid). All the patients were treated with metoprolol tartrate (25 mg, bid) to control the symptoms and signs of hyperthyroidism. Patients were treated for one month. Clinical symptoms and potential side effects were monitored. Serum thyroid hormone levels were measured before and after the treatments. Results: Clinical hyperthyroidism symptoms were improved in both groups, with or without potassium bromide. Patients in the combined treatment group displayed improved clinical hyperthyroidism symptoms 10 days earlier on average (p<0.05). Furthermore, blood thyroid hormone levels decreased to normal levels in 93% (28/30) of patients in the combined treatment group, compared with only 37% (5/30) of patients in the methimazole only group (p<0.05). Conclusions: Treatment of patients with Graves’ disease with a novel combination therapy consisting of potassium bromide and methimazole resulted in a rapid improvement in clinical symptoms and decreased blood thyroid hormone levels to homeostatic levels faster than methimazole treatment alone.