Pharmacology Endocrinology d557b288 The thyroid inhibitor which produces the fastest response is A Lugol's iodine B Propylthiouracil C Radioactive iodine D Lithium carbonate High-Yield Explanation IODINE AND IODIDES Though iodine is a constituent of thyroid hormones, it is the fastest acting thyroid inhibitor. Ref:- kd tripathi; pg num:-254