Main adverse reactions of Iodine-131 therapy for hyperthyroidism

The main adverse reactions associated with ¹³¹I therapy for hyperthyroidism include hypothyroidism, radiation-induced thyroiditis, and worsening of ophthalmopathy (Graves’ ophthalmopathy).

1. Hypothyroidism: This primarily results from radiation-induced destruction of thyroid cells by iodine-131.

2. Radiation-induced thyroiditis: This commonly occurs 7–10 days after administration of the radiopharmaceutical and may persist for up to three weeks, manifesting as thyroid pain and dysphagia.

3. Worsening of ophthalmopathy: Radioactive iodine-131 therapy for thyrotoxicosis is a known factor that may exacerbate and accelerate the progression of Graves’ ophthalmopathy.

In addition, other adverse reactions may occur following ¹³¹I therapy for hyperthyroidism. Patients experiencing any physical discomfort should promptly seek medical evaluation at a hospital and receive appropriate management under physician guidance.