Medical Pharmacology: Thyroid Pharmacology Practice Questions

Thyroid hormones:
1. Major thyroid hormone form secreted by the thyroid gland: 3, 5, 3', 5'-tetraiodothyronine (thyroxine,T₄)
2. Peripheral (extra-thyroidal) form resulting from deiodination of T₄: 3, 5, 3'-triiodothyronine (T₃).
3. Both
4. Neither
Inactive thyroid hormone form: 3, 3', 5'-triiodothyronine (reverse triiodothyronine [rT₃]).
1. True
2. False
Thyroid follicular cells:
1. Synthesize and secrete thyroid hormones
2. Concentrate iodide (I^-) utilizing an active transport mechanism.
3. Both
4. Neither
Major clinical use/uses of thyroid hormone:
1. Hormone replacement treatment for hypothyroid patients.
2. For thyroid stimulating hormone (TSH) suppression treatment for thyroid cancer patients.
3. Both
4. Neither
Levothyroxine: Most appropriate for hormone replacement treatment because:
1. Consistent potency
2. Extended duration of action
3. Both
4. Neither
Levothyroxine treatment depends upon deiodinase 1 and deiodinase 2 (Dio1, Dio2) for conversion of T₄ to T₃ allowing for consistent serum levels of free T_{3
.}
1. . True
2. False
Concerning hypothyroidism during pregnancy: a higher dosage of levothyroxine is typically needed in pregnant patients.
1. True
2. False
Myxedema coma, although rare, may be associated with long-standing severe hypothyroidism.
1. True
2. False
Myxedema coma treatment:
1. IV thyroid hormone administration (levothyroxine)
2. Occasionally, liothyronine may be added in administered until the patient appears stable and conscious.
3. Both
4. Neither
Early intervention in congenital hypothyroidism involves normalization of serum T₄ using levothyroxine.
1. True
2. False