What is commonly used to rapidly control tachycardia in Graves disease?

What is commonly used to rapidly control tachycardia in Graves disease?

• A. Methimazole
• B. Levothyroxine
• C. Propranolol
• D. Propylthiouracil

Answer: (C)

Rapid control of tachycardia in Graves disease comes from blocking the adrenergic effects of excess thyroid hormone. Propranolol, a nonselective beta-blocker, quickly reduces heart rate and palpitations by inhibiting beta-adrenergic receptors. It also lowers peripheral conversion of T4 to T3 at higher doses, giving an additional thyroid-state benefit. In contrast, medications that inhibit thyroid hormone synthesis (methimazole or propylthiouracil) take longer to affect symptoms and aren’t used for immediate rate control, while levothyroxine would worsen tachycardia by increasing thyroid hormone levels.

Rapid control of tachycardia in Graves disease comes from blocking the adrenergic effects of excess thyroid hormone. Propranolol, a nonselective beta-blocker, quickly reduces heart rate and palpitations by inhibiting beta-adrenergic receptors. It also lowers peripheral conversion of T4 to T3 at higher doses, giving an additional thyroid-state benefit. In contrast, medications that inhibit thyroid hormone synthesis (methimazole or propylthiouracil) take longer to affect symptoms and aren’t used for immediate rate control, while levothyroxine would worsen tachycardia by increasing thyroid hormone levels.