<prompt> Conversion of T4 to T3 is inhibited by all except:PropranololPropylthiouracilAmiodaroneMethimazole  <response>: Ans. D MethimazoleRef: KDT 8e p252-253Methimazole inhibits only thyroid peroxidase whereas propylthiouracil inhibits thyroid peroxidase as well as 5-deiodinase. Later is involved in peripheral conversion of T4 to T3 Katzung 12e p688, Goodman Gilman 12e p1150 