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Abstract

BACKGROUND: Graves’ disease, a common cause of hyperthyroidism, is treated with radioactive iodine (RAI) or antithyroid drugs like methimazole, but comparative outcomes guide optimal therapy.OBJECTIVE: To compare efficacy and safety of RAI versus methimazole in patients with Graves’ disease, focusing on remission, hypothyroidism, treatment failure, and symptom improvement.METHODOLOGY: This retrospective study (January 2022–July 22, 2025) included 153 patients with Graves’ disease, confirmed by thyroid scan, suppressed TSH, and elevated free T4, presenting to the internal medicine clinic at Northwest General Hospital & Research Centre, Peshawar. Eighty patients received RAI, and 73 received methimazole (10–30 mg/day). Outcomes at six months included remission, hypothyroidism, and treatment failure, time to remission, relapse, and symptom improvement. Chi-square tests, t-tests, and Kaplan-Meier analysis were used.RESULTS: RAI achieved treatment success in 80.0% of patients (64/80), though the majority of these (48/80, 60.0%) developed hypothyroidism, a known consequence of ablative therapy, versus 65.8% for methimazole (48/73; all euthyroid) (P=0.04). Hypothyroidism occurred in 60.0% of RAI patients (48/80) but none in the methimazole group (P<0.001). Treatment failure was lower with RAI (10.0%) than methimazole (34.2%) (P<0.01). RAI had shorter mean time to treatment success (2.8 months) versus methimazole (4.1 months) (P<0.01). Symptom improvement was higher with RAI (85.0%) than methimazole (70.0%) (P=0.03).
CONCLUSIONS: RAI offers early relief in symptoms and biochemical euthyroidism but carries a higher hypothyroidism risk. Methimazole preserves thyroid function but has higher failure rates. Treatment should be individualized.KEYWORDS: graves’ disease, radioactive Iodine, hyperthyroidism, methimazole, remission