Which medication is indicated for hyperthyroidism?

Methimazole is indicated for the treatment of hyperthyroidism because it functions as a thionamide, inhibiting the synthesis of thyroid hormones by blocking the enzyme thyroid peroxidase. This action reduces the production of T3 and T4, which are elevated in hyperthyroidism. By decreasing these hormones, methimazole helps to manage the symptoms associated with an overactive thyroid, such as weight loss, anxiety, and palpitations.

In contrast, levothyroxine is a synthetic form of the thyroid hormone thyroxine (T4) and is used to treat hypothyroidism, not hyperthyroidism. Metformin is primarily used in the management of type 2 diabetes and has no application in treating thyroid disorders. Propranolol is a beta-blocker that can be used to alleviate certain symptoms of hyperthyroidism, such as tachycardia and anxiety, but it does not address the underlying hormone production and is not a primary treatment for the condition. Thus, methimazole is the most appropriate option for directly managing hyperthyroidism.