How often should TSH levels be monitored in patients with a history of Graves' disease who are in remission with negative TSI/TBII antibodies and off medical therapy?

If Anti-thyroid drugs are discontinued when an TSH receptor antibodies are still positive, recurrent hyperthyroidism often develops within a few months. On the other hand, if the drug is discontinued when antibodies are negative (not “normal“ but still detectable), then recurrent hyperthyroidism is less common (perhaps 20%) and the time to recurrence is much longer: often years later. Therefore, in this circumstance, thyroid function tests should be checked every 4–6 months or even every 6-12 months. However, patients should be advised to be sure to contact their physician if hyperthyroid symptoms occur before the next routine monitoring is scheduled to be done. Also, If antithyroid therapy is resumed after more than a six month interval after the drug has been discontinued, the risk of severe side effects (Agranulocytosis, hepatotoxicity) is the same as if the patient were starting a new course of therapy.