Thyroid Disorders Part 2 Flashcards
(25 cards)
the treatment of choice for patients with very large glands or multinodular goiters.
near-total thyroidectomy
done by withdrawing blood from a vein in the
arm. These blood tests help to diagnose thyroid diseases.
THYROID BLOOD TEST
show the size and condition of the goiter, overactivity of some parts or whole thyroid.
THYROID SCAN & ULTRASOUND-
a procedure that involves taking small samples of
thyroid nodules if present. The samples are sent to a laboratory for examination
BIOPSY
A synthetic T4, it should be taken 30min before or 1 hour after meals
Levothyroxine (Levoxyl)
synthetic T3, it is used for emergency states of
hypothyroidism. Short half-life
Liothyronine (Cytomel, Triostat)
Liothyronine is not used alone for long term treatment
because of increase risk for cardiac side effect. T/F
True
Ratio of Liotrix
4:1 ratio (T4:T3)
Where Desiccated Thyroid is sourced
Animal
Thioamides
Propylthiouracil (Generic)
Methimazole (Tapazole, Tapdin)
Carbimazole
Inhibit the enzyme thyroid peroxidase (Inhibit
organification and coupling)
Blocks peripheral conversion of T4 to T3
(PTU)
Thioamides
Pharmacokinetics:
Almost completely absorbed in the GIT
Can cross placental barrier (lesser with PTU)
Methimazole 10x more potent than PTU
PTU more protein-bound.
Thioamides
Used for treatment of mild thyrotoxicosis and in
preparation of surgery.
Propylthiouracil is relatively safe and preferred in
pregnancy.
Thioamides
ADVERSE EFFECTS:
1. maculopapular rash
2. agranulocytosis
3. hepatitis (PTU)
4. cholestatic jaundice (Methimazole)
5. vasculitis
Thioamides
MOA:
- Block uptake of iodide by the
gland by competitive inhibition
- Effects can be overcome by large
doses of iodides
Inorganic Anions
MOA:
- acutely blocks release of thyroid hormone from the gland by
inhibiting thyroglobulin proteolysis (> 6 mg daily),
- inhibit iodide organification
Iodides
A/E: Aplastic anemia (that is why it is rarely used)
Inorganic Anions
CAUTION:
- Not used alone because the gland will
escape from inhibition after 2-8 weeks
- Chronic use in pregnancy should be avoided – fetal goiter
Iodides
inhibits conversion of T4 to T3 in the liver, kidney, brain
and pituitary
inhibition of hormone release
Iodinated Contrast Dye
Useful in thyroid storms (adjunctive therapy)
Iodinated Contrast Dye
Inhibits T4 to T3
Beta blockers and Glucocorticoids
the only isotope used in treatment of thyrotoxicosis
Sodium iodide 131
MOA:
- Trapped within the gland and enter
intracellularly and delivers strong
beta radiations destroying follicular
cells
Radioactive Iodine
accelerate T4 breakdown (by hepatic enzyme induction) and may be helpful both as sedatives and to lower T4 levels.
Barbiturates
