Drugs for Thyroid Disorders Flashcards
What is the indication for propranolol in the context of the thyroid
Widely used to reduce heart rate and tremor
during thyroid storm
MOA of propranolol
Ø Inhibits conversion of T4 to the more biologically active
hormone, T3, which occurs in peripheral tissues.
Ø May help reverse reduced systemic vascular resistance
What can amiodarone cause
e type II amiodarone induced thyrotoxicosis
– Occurs from actual thyroid tissue destruction
What is the daily recommended intake of iodine?
What is in amiodarone?
- 0.15 mg
2. Each 200 mg tablet = 74.4 mg (37.3%) of iodine, with 7.4 mg (10%) per day being released as free iodine.
What group is methimazole part of?
What does that group do
Thioamide group of medications
Blocks iodide organification
Indication for methimazole
Taken before thyroid surgery
– Lowers thyroid hormone levels
– Minimizes the effects of thyroid manipulation
What enzyme does methimazole inhibit
Thyroperoxidase (TPO)
MOA of potassium iodide
stable form of iodine
Blocks iodine uptake
Indications for potassium iodide
Ø Used as a treatment for hyperthyroidism
Ø Used as a treatment for iodine deficiency
Ø Also used along with anti-thyroid medicines to prepare the thyroid gland for surgical removal
What does potassium iodide protect the thyroid from
radiation exposure
What is the most sensitive screening test for hyperthyroidism and primary hypothyroidism
TSH
What is levothyroxine used to treat
Used to treat thyroid hormone deficiency
MOA of levothyroxine
How long can the maximum effect take
- Manufactured form of the thyroid hormone –> thyroxine (T4)
Converted to triiodothyronine (T3) - up to six weeks
Contraindication fo radioactive iodine therapy for thyroid cancer
pregnant women
What is a common drug that impairs levothyroxine absorption
Cholestyramine
