Screening is not recommended in women less than age 50 or in men because the prevalence of unsuspected symptomatic thyroid dysfunction is low in these populations. The optimal management of patients without goiter or ocular findings of Graves' disease is uncertain, but the author recommends repeat measurements of TSH, T 4 and T 3 every six to 12 months. The author notes that previous studies suggested that the addition of thyroid hormone to long-term methimazole or propylthiouracil therapy in patients with Graves' disease increased the likelihood of remission when antithyroid drug therapy was discontinued. More recently, several large randomized studies have failed to confirm that levothyroxine promotes remission in patients receiving antithyroid therapy. The author believes the concomitant use of thyroid hormone in these patients is unjustified, especially in light of the higher likelihood of serious adverse effects with higher doses of antithyroid drugs.
Evidence supports the use of methimazole over propylthiouracil.
Methimazole has been associated with higher cure rates, and this agent requires less frequent doses and may carry a lower risk for agranulocytosis. With respect to the treatment of hypothyroidism, the author asserts that studies pointing to improved efficacy with the addition of levotriiodothyronine require further confirmation before this hormone is added to thyroid replacement therapy. Variations in the potency among compounds that contain both hormones limit the utility of this approach. Combined preparations may become the choice in the future when these preparations are more standardized. In the absence of these findings, follow-up every six to 12 months is appropriate because most occult carcinomas are papillary and rarely aggressive.