Name one common medication used to treat hyperthyroidism.

Methimazole is a common medication used to treat hyperthyroidism. It functions as an antithyroid drug, inhibiting the production of thyroid hormones by blocking the enzyme thyroperoxidase, which is critical in the synthesis of these hormones. By reducing the levels of thyroid hormones, Methimazole alleviates the symptoms of hyperthyroidism, such as increased heart rate, anxiety, and weight loss.

In contrast, Levothyroxine is prescribed for hypothyroidism, where there is an underproduction of thyroid hormones, making it inappropriate for treating hyperthyroidism. Metformin is primarily used for managing type 2 diabetes and does not address thyroid hormone levels, while insulin is used to regulate blood glucose levels in diabetes, not in hyperthyroid conditions. Thus, Methimazole is specifically targeted for hyperthyroidism management, making it the correct choice.