From the Guidelines
Propranolol is suitable for the management of Graves' disease and prevention of thyroid storm, but only as an adjunctive therapy rather than a primary treatment. For Graves' disease, propranolol (typically 20-40 mg taken 3-4 times daily) helps control symptoms like tachycardia, tremors, anxiety, and heat intolerance by blocking beta-adrenergic receptors, as noted in the 2022 study published in Hypertension 1. However, it does not address the underlying autoimmune process or reduce thyroid hormone production. For definitive treatment of Graves' disease, antithyroid medications (methimazole or propylthiouracil), radioactive iodine therapy, or thyroidectomy are necessary.
In thyroid storm, propranolol (60-80 mg orally every 4-6 hours or 1-2 mg IV slowly) is an essential component of management to control cardiovascular symptoms, but must be used alongside antithyroid drugs, corticosteroids, and supportive care. Propranolol is particularly valuable in thyroid crisis because it not only blocks the peripheral effects of excess thyroid hormone but also inhibits the conversion of T4 to the more active T3. The use of beta-blockers in thyroid storm is also supported by the 2010 European Heart Journal study 1, which highlights the importance of controlling ventricular rate in patients with hyperthyroidism.
Some key points to consider when using propranolol in patients with Graves' disease or thyroid storm include:
- Caution is needed when using propranolol in patients with asthma, COPD, heart failure, or diabetes, as it may exacerbate these conditions.
- Propranolol should be used at the lowest effective dose to minimize side effects and maximize benefits.
- Regular monitoring of thyroid hormone levels and adjustment of propranolol dosage as needed is crucial to ensure optimal management of Graves' disease and prevention of thyroid storm.
- The 2017 Journal for ImmunoTherapy of Cancer study 1 notes that thyroiditis is a self-limiting process and leads to permanent hypothyroidism after an average of 1 month after the thyrotoxic phase, highlighting the importance of close monitoring and adjustment of treatment as needed.
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 is suitable for the management of Graves' disease and prevention of thyroid storm as it can help mask certain clinical signs of hyperthyroidism. However, abrupt withdrawal of propranolol may be followed by an exacerbation of symptoms of hyperthyroidism, including thyroid storm 2.
- Key points:
- Propranolol can mask clinical signs of hyperthyroidism
- Abrupt withdrawal may lead to exacerbation of symptoms, including thyroid storm
- Propranolol may alter thyroid-function tests It is essential to use propranolol with caution and under close medical supervision to avoid any potential complications.
From the Research
Propranolol in Graves' Disease Management
- Propranolol is used in the management of Graves' disease to prevent thyroid storm, as seen in a case report where a patient with Graves' disease presented with thyrotoxic periodic paralysis and cardiomyopathy, and was treated with propranolol, propylthiouracil, and hydrocortisone 3.
- The drug is a beta-adrenergic receptor blocker and blocks the peripheral conversion of thyroxine (T4) to triiodothyronine (T3) in high doses, making it an integral part of treatment for thyrotoxicosis 3.
- Propranolol is also used to manage hyperthyroidism by reducing the symptoms of thyrotoxicosis, such as tachycardia and tremors, as mentioned in a study on the medical management of Graves' disease 4.
Prevention of Thyroid Storm
- Propranolol is used in combination with other medications, such as propylthiouracil and potassium iodide, to prevent thyroid storm in patients with Graves' disease 5.
- However, the use of beta blockers, including propranolol, can be beneficial or devastating in thyroid storm patients, depending on the presence of low cardiac output or high cardiac output heart failure, as highlighted in a case report of iatrogenic cardiac arrest during thyroid storm 6.
- Clinical awareness, prompt echocardiography, and the use of shorter half-life beta blockers can prevent rapid cardiac deterioration in thyroid storm patients 6.
Long-term Remissions
- Propranolol alone can induce lasting remissions in some patients with Graves' hyperthyroidism, as seen in a study where eight patients had a biochemical remission that lasted 30-48 months after propranolol withdrawal 7.
- The remissions are likely spontaneous, as propranolol is devoid of antithyroid and immunosuppressive actions, and no biological parameter was found to predict the outcome 7.