When is Radioactive Iodine used to treat Thyrotoxicosis?
Radioactive iodine is a very effective treatment for thyrotoxicosis; it works because the thyroid cells trap the radioactive iodine, which kills them. It can be used in all age groups and is even safe in children. Its role is limited in massive toxic goitres, particularly if there is a significant retrosternal element.Radioactive iodine does have an initial failure rate of 20% and therefore one in five patients needs a futher dose of radioactive iodine repeated.Most guidlines suggest stopping anti-thyroid drugs for 3 to seven day prior to giving radioactive iodine.The reasno for this is that radio-active iodine is more effective if antithyroid drugs are withdrawn. There is a down side to this practicein that a prolonged interval of antithyroid drug cessation is the risk of exacebation of the hyperthyroidism. Radio-active iodineis completely contraindicated in pregnancy and women should refrain from getting pregnant for at least 6 months after treatment. If the patient is breast-feeding
