Medical Pharmacology: Thyroid Physiology and Pharmacology

Thyroid hormone more likely to be completely absorbed following oral administration:
1. thyroxine
2. triiodothyronine
3. both equally absorbed
4. neither absorbed orally, requires parenteral administration
Effective hyperthyroidism on thyroxine (T4) metabolic clearance:
1. increased
2. decreased
3. no change
Example(s) of (a) drug(s) that increases metabolism of T4 and T3:
1. rifampin
2. carbamazepine
3. phenytoin
4. A & C
5. A, B & C
Inhibition of pituitary TSH release:
1. L-DOPA
2. somatostatin
3. dopamine
4. corticosteroids
5. all the above
Inhibition of thyroid hormone synthesis or release:
1. amiodarone
2. lithium
3. aminoglutethimide
4. iodides
5. all of the above
Associated with 5'-deiodinase inhibition:
1. rifampin
2. iopanoic acid
3. dopamine
4. cholestyramine
5. salicylates
Associated with increased TBG (thyroxine-binding globulin):
1. androgens
2. colestipol
3. interleukin 2
4. amiodarone
5. estrogens
Eyes: periorbital edema; exophthalmos; wide stare:
1. thyrotoxicosis
2. hypothyroidism
Respiratory system: decreased vital capacity; dyspnea
1. thyrotoxicosis
2. hypothyroidism
CNS: lethargy; neuropathy
1. thyrotoxicosis
2. hypothyroidism
Reproductive system: hypermenorrhea; oligospermia; decreased enamel steroid metabolism
1. thyrotoxicosis
2. hypothyroidism
Gastrointestinal system: increased appetite; hypoproteinemia
1. thyrotoxicosis
2. hypothyroidism
Skin: pale, cool
1. thyrotoxicosis
2. hypothyroidism
Inhibits iodide transport into thyroid gland:
1. ipodate
2. thiocyanate
3. thioamides
4. A & C
5. A, B & C
More potent thyroid hormone:
1. T4
2. T3
3. equal potent
Displacement of thyroid hormones (thyroxine, triiodothyronine) from TBG; may cause hyperthyroxinemia:
1. methadone
2. sucralfate
3. lithium
4. furosemide
5. none of the above
Preparation of choice for thyroid replacement.
1. dessicated thyroid
2. liothyronine
3. levothyroxine
4. propylthiouracil
5. methimazole
Inhibits conversion T4 to T3 in the liver, kidney, pituitary gland, brain;may be useful in treating hyperthyroidism; routinely used as a radiographic contrast agent
1. methimazole
2. propylthiouracil
3. iopanoic acid
4. perchlorate
5. liothyronine
Thioamide less likely to cross the placental barrier:
1. methimazole
2. propylthiouracil
3. both are equally likely
Competitive inhibition of iodide uptake by the thyroid:
1. perchlorate
2. pertechnetate
3. thiocyanate
4. A & C
5. A, B & C