Do you recommend prescribing methimazole to prevent iodinated contrast media-induced exacerbation of thyrotoxicosis in patients with pre-existing hyperthyroidism?  

Yes. If someone has pre-existing UNTREATED hyperthyroidism and elderly, Methimazole should be started. The exact dose has not been proven but I use 5 mg daily for 2 months. Urinary iodine after a CT scan with contrast has been documented to be high at 2 weeks and 1 month but not 2 months post infusi...