Fast Five Quiz: How Much Do You Know About Hyperthyroidism?

Romesh Khardori, MD, PhD


May 08, 2017

Treatment of hyperthyroidism includes symptom relief, as well as antithyroid pharmacotherapy, radioactive iodine-131 therapy (the preferred treatment of hyperthyroidism among US thyroid specialists), or thyroidectomy. However, antithyroid medications are not effective in thyrotoxicosis in which scintigraphy shows low uptake of iodine-123, as in patients with subacute thyroiditis, because these cases result from release of preformed thyroid hormone.

Antithyroid drugs (eg, methimazole and propylthiouracil) are used for long-term control of hyperthyroidism in children, adolescents, and pregnant women. In adult men and nonpregnant women, they are used to control hyperthyroidism before definitive therapy with radioactive iodine. The antithyroid drug dose should be titrated every 4 weeks until thyroid functions normalize. Some patients with Graves disease go into remission after treatment for 12-18 months, and the drug can be discontinued. Notably, half of the patients who go into remission experience a recurrence of hyperthyroidism within the following year.

Methimazole is more potent than propylthiouracil and has a longer duration of action. In addition, methimazole is taken once daily, whereas propylthiouracil is taken two to three times daily; consequently, patient compliance is often better with methimazole than with propylthiouracil.

Many of the neurologic and cardiovascular symptoms of thyrotoxicosis are relieved by beta-blocker therapy. Before such therapy is initiated, the patient should be examined for signs and symptoms of dehydration that often occur with hyperthyroidism. After oral rehydration, beta-blocker therapy can be started. Beta-blocker therapy should not be administered to patients with a significant history of asthma. Calcium channel blockers (eg, verapamil and diltiazem) can be used for the same purposes when beta-blockers are contraindicated or poorly tolerated. These therapies should be tapered and stopped once thyroid functions are within the normal range.

For more on the treatment of hyperthyroidism and thyrotoxicosis, read here.


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