Which of the following medications decreases their action while taking thyroid hormone?
A. Metformin
B. Warfarin
C. Zoloft
D. Epinephrine
Correct Answer: A. Metformin
Metformin, an oral hypoglycemic drug when taken with a thyroid hormone decreases their action.
Options B, C, & D: Warfarin (an anticoagulant), Zoloft (an antidepressant), and Epinephrine (a sympathomimetic) increases their action when taken with a thyroid hormone.