Flashcards in Thyroid Pharmacology Deck (24):
Thyroid hormones are best absorbed by the _____________.
Levothyroxine should be taken on a(n) ______________.
What impairs the absorption of levothyroxine?
The activating deiodinases are inhibited by _______________.
glucocorticoids, beta-blockers, amiodarone, caloric deprivation, and chronic illness
T4 requires ___________ to become effective.
Be careful giving T4 to those with ____________.
underlying cardiac illness
Why is it necessary to give increased doses of T4 to pregnant women?
Because the excess estrogen induces greater thyroid-binding globulin and excess metabolism of thyroxine
If you give a large dose of thyroxine to someone having a thyroid crisis, what else do you need to give?
Corticosteroids to prevent adrenal insufficiency
There is no evidence to support that the brand name of thyroxine ____________.
The pharmaceutic name for triiodothyronine is ____________.
Which has better bioavailability, T3 or T4?
Why is T3 more potent than T4?
It has a higher affinity for thyroid-hormone receptors.
How do methimazole and propylthiouracil work?
They inhibit thyroid peroxidase, specifically where it organifies iodide.
What can lead to permanent destruction of the thyroid?
I(131) – radioactive iodide
Which thyroid peroxidase inhibitor is best for pregnant women?
Propylthiouracil (Pregnancy = Propylthiouracil)
Doctors occasionally give __________ before administering radioactive iodine.
What causes unbinding from TBG?
What drugs can cause euthyroid sick syndrome?
The other name for T3 is _____________.
Methimazole is generally the preferred medication because of lack of ______________.
hepatotoxicity, efficacy at lower doses, and once-daily dosing
_________, which rises in pregnancy, stimulates production of TBG.
Remember that methimazoles and thionamides are only for hyperthyroidisms from excess _____________.
production, not release
The most dangerous side effect of methimazole and PTU is _____________.