What beta blocker (beta-adrenergic blocking agent) is used to treat hyperthyroidism?

From the Guidelines

Beta blockers, specifically propranolol, are the preferred treatment for managing symptoms of hyperthyroidism, as they effectively control the sympathetic nervous system overactivity caused by excess thyroid hormones, reducing heart rate, tremors, anxiety, heat intolerance, and palpitations 1.

Key Considerations

• The goal of therapy is to lower the heart rate to nearly normal, which will cause the tachycardia-mediated component of ventricular dysfunction to improve 1.
• Non-selective beta blockers like propranolol are generally preferred, but cardioselective options like metoprolol can be used in patients with respiratory conditions.
• Beta blockers should be continued until thyroid hormone levels normalize with definitive treatment (antithyroid drugs, radioactive iodine, or surgery) 1.

Dosage and Administration

• Propranolol is typically started at 10-40 mg three to four times daily, with doses adjusted based on symptom control and heart rate response 1.
• The total daily dose usually ranges from 40-240 mg.

Monitoring and Side Effects

• Patients should be monitored for potential side effects including fatigue, dizziness, and bradycardia 1.
• Doses should be tapered rather than abruptly discontinued when treatment is complete.

Additional Considerations

• Beta blockers are effective in controlling the ventricular rate in patients with hyperthyroidism and atrial fibrillation, and are particularly important in cases of thyroid storm 1.
• Thyroiditis is self-limiting and has two phases, and patients may benefit from beta blockers if symptomatic during the hyperthyroid phase 1.

From the FDA Drug Label

Thyrotoxicosis: Beta-adrenergic blockade may mask certain clinical signs of hyperthyroidism. Therefore, abrupt withdrawal of propranolol may be followed by an exacerbation of symptoms of hyperthyroidism, including thyroid storm. Propranolol may change thyroid-function tests, increasing T4 and reverse T3, and decreasing T3

• Propranolol can be used as a beta blocker for hyperthyroidism to mask certain clinical signs, but it may not address the underlying condition.
• It is essential to be cautious when using propranolol in patients with hyperthyroidism, as abrupt withdrawal may lead to an exacerbation of symptoms, including thyroid storm 2.

From the Research

Beta Blockers for Hyperthyroidism

• Beta blockers are widely used as adjuvant therapy in the treatment of hyperthyroidism, often combined with antithyroid drugs, iodine, or before radiotherapy or surgical resection of the thyroid gland 3.
• In mild cases of hyperthyroidism, propranolol may be used as a single drug, with oral doses of 40 to 80 mg every 6 or 8 hours 3.
• Various beta blockers, including atenolol, metoprolol, acebutolol, oxprenolol, nadolol, and timolol, have been shown to produce a beneficial clinical response equal to that of propranolol 4.
• Beta blockers can reduce resting heart rate, improve nervousness and tremor, and reduce the frequency of paralysis in patients with thyrotoxic periodic paralysis 4.
• They may also reduce circulating tri-iodothyronine (T3) concentration and have endocrinological effects on gastrin, cyclic AMP, catecholamines, and other hormone levels 4, 5.
• The choice of beta blocker may depend on the individual patient's response, as different beta blockers can have varying effects on serum T3 and rT3 levels 6, 5.
• Hyperthyroidism may affect the kinetics of certain beta blockers, such as propranolol and metoprolol, but not others like atenolol 7.
• Contraindications for the use of beta blockers in hyperthyroidism include asthma, chronic obstructive pulmonary disease, and congestive heart insufficiency 3.