Thyroid Drugs

Question 1

TH Replacement Therapy (contraindications)

Answer 1

Obesity, vaginal bleeding, depression

Question 2

Synthetic T4 (4)

Answer 2

Levothroid, Levoxyl, Synthroid, Unithroid

Question 3

Synthetic T3 (2)

Answer 3

Cytomegalovirus, Triostat

Question 4

K-I (potassium iodide, SSKI) (uses)

Answer 4

Use: achieve Wolff-Chaikoff effect in hyperthyroidism (I increase temporarily inhibits T3/4 synthesis)

Question 5

Radioactive Iodide (uses)

Answer 5

Uses: Graves’ disease, toxic nodules, thyroid cancer

Question 6

Propylthiouracil (PTU)

Answer 6

Mechanism: inhibits thyroid peroxidase and iodine organification (thus TH synthesis), and inhibits peripheral T3/T4deiodination
Use: hyperthyroid
Side effects: macupapular pruritic rash, fatal hepatitis, elevated liver enzymes, agranulocytosis.
-Safer than methimazole for pregnancy (doesnt cross placenta)

Question 7

Methimazole

Answer 7

Mechanism: inhibits thyroid peroxidase and iodine organification (thus TH synthesis)
Use: hyperthyroid
Side effects: macupapular pruritic rash, fatal hepatitis, elevated liver enzymes, agranulocytosis. Also can cause aplasia cutis (lack of skin on head)
-Safer than PTU except for pregnancy (crosses placenta)