<prompt> Which of the following drugs inhibit 5-deiodinase?PropylthiouracilMethimazoleLugols iodineRadioactive iodine  <response>: Ref: KDT 6e p249, 250 For the peripheral conversion of T4 to T3 the enzyme needed is 5-deiodinase. It is inhibited by Propylthiouacil, Propanolol, Amiodarone. 