From the Guidelines
Beta blockers are commonly used to manage symptoms in hyperthyroidism, with propranolol being the most widely studied nonselective beta-blocker for this condition. According to the most recent and highest quality study, 1, propranolol is used to treat the increased heart rate and tremor associated with thyrotoxicosis, hyperthyroidism, thyroiditis, and Graves’ disease. The medication helps reduce heart rate, palpitations, tremors, anxiety, and heat intolerance while definitive treatment for the underlying hyperthyroidism takes effect. Beta blockers work by blocking the action of adrenaline on beta-adrenergic receptors, counteracting the stimulatory effects of thyroid hormone on the cardiovascular system.
Some key points to consider when using beta blockers for hyperthyroidism include:
- The goal of therapy is to lower the heart rate to nearly normal, which can cause the tachycardia-mediated component of ventricular dysfunction to improve, as noted in 1.
- Beta blockers are associated with rapid improvement in cardiac and neuro-related symptoms, as seen in 1.
- Patients with asthma, diabetes, or certain heart conditions should use beta blockers cautiously, and dose adjustments may be needed as thyroid function normalizes with definitive treatment.
- Beta blockers are particularly useful in thyroid storm (severe hyperthyroidism) and before thyroid surgery, as mentioned in 1 and 1.
In terms of specific dosing, propranolol (10-40 mg every 6-8 hours), atenolol (25-100 mg daily), or metoprolol (25-100 mg twice daily) are typically prescribed to control the sympathetic nervous system effects of excess thyroid hormone. However, the exact dosing may vary depending on the individual patient's needs and response to treatment, as discussed in 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. Yes, beta blockers, such as propranolol, are used to manage symptoms in hyperthyroidism, specifically to mask certain clinical signs of the condition 2.
- They may help alleviate symptoms such as rapid heart rate and tremors.
- However, beta blockers do not treat the underlying cause of hyperthyroidism and may mask certain clinical signs, making it important to monitor patients closely.
From the Research
Use of Beta Blockers in Hyperthyroidism
- Beta blockers are used as adjuvant therapy in the treatment of hyperthyroidism, often combined with antithyroid drugs, iodine, or before radiotherapy and surgery 3.
- They are effective in treating hypermetabolic symptoms in various hyperthyroid states, offering significant symptomatic relief when used alone or as adjuvants to other treatments 4.
- The principal mechanism of action of beta blockers in hyperthyroidism is to antagonize beta-receptor-mediated effects of catecholamines, providing relief from symptoms such as palpitations, tremors, and anxiety 4.
Administration and Dosage
- Oral doses of beta blockers, such as propranolol, are typically 40 to 80 mg every 6 or 8 hours 3.
- Intravenous application of short-acting beta blockers may be more useful in certain situations 3.
- The drug is applied until remission of all symptoms of the disease, with propranolol showing minimal untoward effects in this context 3.
Contraindications and Considerations
- Contraindications for the application of beta blockers include asthma, chronic obstructive pulmonary disease, and congestive heart insufficiency 3.
- Beta blockers do not alter the synthesis or secretion of thyroid hormone by the thyroid gland but may affect thyroxine metabolism, with some agents decreasing thyroxine to triiodothyronine conversion 4.