Why is the Wolff Chaikoff effect temporary? What is the typical does of daily iodine needed for the W-C effect? what does the dose have to be over? What are the two solutions for the WC effect? What are the adverse reactions of the WC effect? What is the thyroid peroxidase blocker? What is the mechanism of action of propylthiouracil? What is the origin of propylthiouracil? What is true of the onset of propylthiouracil and why? Who is propylthiouracil contraindicated in? What are the adverse reactions of Methimazole (MMI)?

1. Why is the Wolff Chaikoff effect temporary?

due to the inevitable thyroid compensation and rebound effects

2. What is the typical does of daily iodine needed for the W-C effect? what does the dose have to be over?

must be greater than 6mg/day, but doses are typically btwn 50-150 mg/day

3. What are the two solutions for the WC effect?

Lugol's solution - 5% I and 10% KI, sodium iodide 1-% NAI

4. What are the adverse reactions of the WC effect?

allergic reactions are common in persons with seafood allergy particulary shelfish, and iodism

5. What is the thyroid peroxidase blocker?

propylthiouracil and methimazole

6. What is the mechanism of action of propylthiouracil?

Out competes the thyroglobulin for the spot of the peroxidase receptor

7. What is the origin of propylthiouracil?

naturally occuring in turnips and cabbage seeds

8. What is true of the onset of propylthiouracil and why?

Slow onset because it must deplete the stores of the T3 and T4 in the colloid before the effects begin

9. Who is propylthiouracil contraindicated in?

women who are pregnant, breast feeding and on 131I treatment

10. What are the adverse reactions of Methimazole (MMI)?

rash, puritis, and arthralgia (common), agranulocytis, hepatitis, or other liver toxicity (rare)