August, 2001

According to the August issue of the Journal of Clinical Endocrinology and Metabolism, some practitioners have systematically provided antithyroid treatment with methimazole in order to increase the effectiveness of radioactive iodine (RAI) treatment prior to providing RAI in patients with Graves' hyperthyroidism. This practice, however, is considered controversial and there is no agreement as to whether it is effective, or perhaps even detrimental.

In a Brazilian study, which gave half the subjects pretreatment, and other group no pretreatment, approximately 80% of both groups achieved a euthyroid (normal range) state in approximately 3 months, and after 1 year, and both groups had similar rates of persistent hyperthyroidism (an average of around 15%), euthyroidism (approximately 29.5%), and hypothyroidism (approximately 55.5%). The reearchers concluded that pretreatment had no effect on either the "cure" time, or the 1-year success rate.

Source: "The Effect of Methimazole Pretreatment on the Efficacy of Radioactive Iodine Therapy in Graves' Hyperthyroidism: One-Year Follow-Up of a Prospective, Randomized Study", Vânia A. Andrade, Jorge L. Gross and Ana Luiza Maia, Endocrine Division, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, 90035-003 Porto Alegre, Brazil
Journal of Clinical Endocrinology and Metabolism, August 2001 Volume 86, Issue 8