Drugs for Thyroid Disorders (Part 02) Flashcards
(30 cards)
Four (4) Drug/s for Hypothyroidism
- Levothyroxine
- Liothyronine
- Liotrix
- Dessicated Thyroid
It should be taken 30 min before or 1 hr after meals. A long half-life.
Levothyroxine
Brand Name/s of Levothyroxine
- Eltroxin
- Euthyrox
- Levoxyl
- Levothroid
- Synthroid
A synthetic T3. Used for emergency states of hypothyroidism. A faster acting but has shorter half-life and is more expensive. Not used alone for long term treatment because of increase risk for cardiac side effect.
Liothyronine
Brand Name/s of Liothyronine
- Cytomel
- Triostat
A fixed ratio preparation. The T3 component proved unnecessary (because T4 is metabolized to T3). T3 component is also disadvantageous because of T3-induced adverse effects.
Liotrix
From animal source. A ratio of T3 and T4 varies with the animal source.
Desiccated Thyroid
Ratio of Thyroglobulin
2:1
Ratio of Pork
2–3:1
Ratio of Beef
4:1
Anti-Thyroid Drugs
- Thioamides
- Inorganic Anions
- Iodides
- Iodinated Contrast Dye
- Beta Blockers and Glucocorticoids
- Radioactive Iodine
It inhibit the enzyme thyroid peroxidase (inhibit organification and coupling). It blocks peripheral conversion of T4 to T3 (PTU). Since the synthesis rather than the release of hormones is affected, the onset of these agents is slow, often requiring 3-4 weeks before stores of T4 are depleted.
Thioamides
Drug/s under Thioamides
- Propylthiouracil
- Methimazole (Tapazole, Tapdin)
- Carbimazole
A/E of Thioamides
- Maculopapular Rash
- Agranulocytosis
- Hepatitis (PTU)
- Cholestatic Jaundice (Methimazole)
- Vasculitis
It blocks the uptake of iodide by the gland by competitive inhibition. Effects can be overcome by large doses of iodides. Useful for iodide-induced hyperthyroidism (amiodarone-induced hyperthyroidism).
Inorganic Anions
Drug/s under Inorganic Anions
- K Perchlorate
- K Thiocyanate
A/E of Inorganic Anions
Aplastic Anemia
It acutely blocks release of thyroid hormone from the gland by inhibiting thyroglobulin proteolysis (> 6 mg daily). It inhibit iodide organification.
Iodides
Drug/s under Iodides
- Strong Iodine Solution (Lugol’s)
- lodone
- KISS (Potassium lodide Saturated Solution)
Chronic use of Iodides in pregnancy should be avoided because it can cause __________.
Fetal Goiter
A/E of Iodides
Acneiform Rash
It inhibits conversion of T4 to T3 in the liver, kidney, brain and pituitary. The inhibition of hormone release. Useful in thyroid storms (adjunctive therapy).
Iodinated Contrast Dye
Drug/s under Iodinated Contrast Dye
- Ipodate (Oragrafin)
- Iopanoic Acid (Telepaque)
- Diatrizoate (Hypaque)
It inhibits T4 and T3.
Beta Blockers and Glucocorticoids