Treatment and Therapy

The aims in treating Graves¡¯ hyperthyroidism is more towards lowering the serum concentrations of thyroid hormones to re-establish a eumetabolic state. These plans include antithyroid drugs (ATDs), radioactive iodine (131I), and thyroid surgery.[11,20,21]

 

a. Antithyroid Drugs[19,22,23,28]

 

-      ATDs, which include methimazole and propylthiouracil, capable in inhibit thyroid hormone biosynthesis. They are useful either as a primary form of therapy or to lower thyroid hormone levels before (and in some of the cases after) radioactive iodine therapy or surgery. Long term ATD therapy may lead to remission in some patients with Graves¡¯ disease. Initially daily doses of methimazole generally range from 10mg to 40 mg, and for propylthiouracil, 100 to 600mg. There is no clear-cut standard for duration of therapy with ATDs, but when used as primary therapy, they are usually given for 6 months to 2 years, although a longer period of administration is acceptable. Some physicians prefer a regimen of combined ATD and thyroid hormone to avoid frequent adjustment of ATD doses. Patients need to be informed about the adverse drug reaction and drug-drug interactions for these drug and if any of the adverse reaction occurs, patients should inform theirs physicians as soon as possible.

 

b. Radioactive Iodine Therapy[23,24,25]

 

-      Radioactive iodine therapy can be said as safe treatment plan. The principal side effect being the early or late development of hypothyroidism, necessitating life-long thyroid hormone replacement following 131I treatment. Treatment with 131I does not cause a reduction in fertility and does not cause cancer, nor has it been shown to produce ill effects in offspring of those so treated prior to pregnancy. It is contraindicated during pregnancy. Its use in individuals under age 20 years, while controversial, is common. Pregnancy needs to be excluded before 131I is administered to young women who are breast-feeding. Elderly patients or individuals at risk for developing cardiac complications may be pretreated with ATDs prior to 131I therapy, especially if hyperthyroidism is severe, to deplete the gland of stored hormone, thereby minimizing the risk of exacerbation of hyperthyroidism due to 131I-induced thyroidistis. In some patients, ATDs may be required for control for several months following radioiodine therapy. A radioactive iodine test is usually performed just prior to the administration of 131I to determine the appropriate dose.

 

c. Surgery[27,28]

 

-      Thyroidectomy is infrequently recommended for patients with Graves¡¯ disease. Specific indications include patients with very large goiters who may be relatively resistant to 131I, those who have coincidental thyroid nodules, pregnant patients allergic to ATDs, and patients who are allergic to ATDs and/or do not wish 131I therapy. The procedure should be performed only by an experienced surgeon and only after careful medical preparation. Patients must be cautioned about potential complications of surgery, including hypoparathyroidism and injury to the recurrent laryngeal nerve. Hyperthyroidism may persist or recur if insufficient thyroid tissue is removed, whereas hypothyroidism usually develops after near-total thyroidectomy.

Figure: Methimazole¡ªone of the antithyroid drugs used in the treatment of Hyperthyroidism.

Figure: Illustration view of the thyroid gland before and after the thyroidectomy. (Figure taken pending permission from www.thyroidmanager.org)

Hyperthyroidism

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Figure: Propylthiouracil¡ªone of the antithyroid drugs used in the treatment of Hyperthyroidism.

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