The safety and efficacy of antithyroid drugs.

Thionamides, selective inhibitors of thyroid peroxidase-mediated iodination by tyrosine residues in thyroglobulin, have been effectively used in the treatment of hyperthyroidism. The choices for initial treatment of patients with Graves' disease differ in various countries, and many physicians around the world prefer to administer thionamide drugs as the first choice of treatment for patients with hyperthyroidism. Although some thyroidologists more often consider radioiodine to be the treatment of choice because of its safety and ease of administration, thionamides remain the mainstay of treatment in thyrotoxic children and adolescents and in hyperthyroid women during pregnancy, postpartum period and lactation. A recent study with continuous thionamide treatment for patients with Graves' disease shows its efficacy, safety and cost-benefit properties. Further studies of the effectiveness of continuous thionamide therapy in patients with thyrotoxicosis need to be designed and implemented to determine indications for such therapy in children, adolescents and adults with diffuse toxic goiter, in particular, in those who have had recurrence of hyperthyroidism after discontinuation of one complete course of treatment.