Long-Term Antithyroid Drug Therapy in the Management of Graves' Hyperthyroidism: An Updated Narrative Review

To review recent developments in the management of Graves' hyperthyroidism, emphasizing long-term antithyroid drug (ATD) therapy and its comparison with radioactive iodine and thyroidectomy.

A search was applied using MEDLINE and manual reference searches for studies published from January 2010 to July 2025. Eligible articles addressed long-term ATD, thyroidectomy, radioiodine therapy, cardiovascular risks in hyperthyroidism or relapse prediction, and thyrotropin-receptor antibody changes.

Long-term treatment with continuous methimazole (≥60 months) resulted in substantially higher sustained remission (<20% relapse) compared with conventional ATD courses (approximately 50% relapse). It produced faster normalization of thyrotropin, greater time spent in euthyroidism, fewer orbitopathy exacerbations, and minimal late adverse events. Both radioiodine therapy and thyroidectomy resulted in high rates of permanent hypothyroidism, while cardiovascular studies underscored the importance of early and sustained correction of hyperthyroidism. Thyrotropin-receptor antibody trajectory patterns, composed of smooth, fluctuating, and smoldering, were strong predictors of relapse and supported individualized extension of ATD therapy.

Continuous ATD treatment for ≥60 months is more effective in inducing sustained long-term euthyroidism and is associated with fewer adverse events and lower relapse risk than conventional 12-18-month courses and ablative treatment, supporting its inclusion as a therapeutic option in future guidelines for Graves' disease management.