Acute Myocarditis Following Methimazole: A Case Report

Hyperthyroidism is an endocrine disorder characterized by hypermetabolism and increased excitability of multiple organs attributable to improper and excessive synthesis and the secretion of thyroid hormones. Methimazole (MMI), one of the first-line antithyroid drugs, is the preferred drug for hyperthyroidism therapy.1 Long-term antithyroid drug treatment is safe and causes adverse effects in only 3% to 5% of patients.2–4 Common adverse reactions to this treatment include rash, itching, joint pain, and transient leukopenia, which are always mild and transient.