A patient with hyperthyroidism is scheduled for radioactive iodine therapy. Which instruction will be included by the nurse to the patient?

Choice A rationale Radioactive iodine (RAI) therapy involves the administration of a radioactive isotope of iodine, I-131, which is selectively taken up by the thyroid gland to destroy overactive thyroid cells. Since the patient's body contains radioactive material, they must follow strict precautions to prevent radiation exposure to others. This includes avoiding close contact with pregnant women and young children for several days to weeks, as they are more susceptible to the harmful effects of radiation. Choice B rationale This is incorrect. Patients are generally advised to stop taking antithyroid medications, such as methimazole or propylthiouracil, several days before RAI therapy. These drugs prevent the thyroid gland from utilizing iodine, which would interfere with the uptake of the radioactive iodine, rendering the treatment ineffective. The goal is to maximize the absorption of the radioactive iodine by the thyroid gland. Choice C rationale This is incorrect. A patient preparing for radioactive iodine therapy must follow a low-iodine diet for one to two weeks before the treatment. High-iodine foods would saturate the thyroid gland with non-radioactive iodine, competing with the radioactive iodine for uptake and significantly reducing the efficacy of the therapy. Limiting iodine intake ensures the thyroid is "hungry" for the radioactive isotope. Choice D rationale While increasing fluid intake is generally a healthy practice, it is not a primary safety instruction for radioactive iodine therapy. The main instruction is to drink fluids and urinate frequently after the procedure. This helps to flush any unabsorbed radioactive iodine from the body more quickly, reducing radiation exposure to other parts of the body, particularly the bladder.