endocrine pharmacology thyroid disease Flashcards
thyroid hormones
- the follicular thyroid cells secrete _____ (_____) and _____ (_____)
- -regulate energy metabolism and growth, from _____ consumption to cardiac _____
- the parafollicular C cells secrete _____
- -regulator of bone mineral homeostasis
thyroxine (T4) triiodothyronine (T3) oxygen contractility calcitonin
- follicular cells of the thyroid gland concentrate _____ (I-) from plasma via a basolateral membrane Na+/I- _____
- _____
- formation og monoiodothyronine (MIT); and diiodothyronine (DIT)
- MIT and DIT associate covalently on _____ via a mechanism known as _____, catalyzed by _____
iodide symporter organification thyroglobulin coupling thyroid peroxidase
- _____ is stored as colloid within follicles in the thyroid gland
- upon stimulation by _____, thyroid follicular cells _____ into lysosomal compartments, where the thyroglobulin is degraded to yield free _____, free _____, and uncoupled _____ and _____
- T3 and T4 are secreted into the plasma, and MIT and DIT are deiodinated to yield free _____
- the thyroid gland secretes more _____ than _____, although T4 is converted to T3 in peripheral tissues
thyroglobulin TSH endocytose T4 T3 MIT DIT iodide T4 T3
hypothyroidism
- syndrome characterized by low circulating levels of _____ and _____
- -rare cases where tissue becomes resistant to thyroid hormones
- -have a _____ slowing down of all body functions
- -infants and children - growth and developmental _____
- –mental retardation is _____
T4 T3 reversible retardation irreversible
hypothyroidism
pathology:
-primary hypothyroidism (_____)
-secondary hypothyroidism (_____)
-tertiary hypothyroidism (_____)
-generalized resistance to thyroid hormones (_____)
–usually caused by a defect in the _____ receptor for _____ and _____
thyroid pituitary hypothalamus peripheral tissues beta T3 T4
hypothyroidism
management:
-replacement with _____ or _____ or thyroid extract products
-infants and children require more _____ per kg than adults
–newborns 6 to 10 ug/kg/day
–adults 1.6 ug/kg/day
-individual variability - need dose adjustment
–dosage adjustment should not take place more frequently than _____
-dosing time: what is the best time for me to dose a patient?
T4 T3 T4 4 to 6 weeks first thing in the morning one hour before they eat because we want the bodys normal conversion mechanism to happen
hypothyroidism
_____:
-rare, high mortality usually in the elderly
–end state of untreated hypothyroidism
-hypothermia, bradycardia, hypotension, hypoventilation and coma
myxedematous coma
hypothyroidism
management:
-_____ (synthroid; levothyroid)
–_____, identical to the T4 secreted by the thyroid gland
-liothyronine [L-triiodothronine] (cytomel)
–synthetic T3
-liotrix (thyrolar)
–synthetic T4/T3 combination preparation
sodium levothyroxine
synthetic T4 hormone
hypothyroidism
- levothyroxine (L-isomer of T4)
- treatment of choice for hypothyroidism
- not ideal for _____
- -_____ tolerated, generally no problems art appropriate dosages
- -_____
- –exacerbation of angina, minimize slow upward dose titration
- —start with very low doses
myxedema
well
coronary heart disease
hypothyroidism
- liotrix (thyrolar) synthetic T4/T3
- -_____ tolerated, generally no problems at appropriate dosages
- adverse effects
- -cardiac arrhythmia, chest pain, palpitation, tachycardia
- -ataxia, fever, headache, insomnia, nervousness
- precaution with _____:
- -increased risk of coronary artery spasm when these agents are used together
well
epinephrine
hypothyroidism: drug interactions
- drug interactions may result in _____ T3/T4
- _____: bile acid sequestrant
- antacids: gastric acidity is essential for T4 absorption/ calcium may chelate
- PPI: _____ (prevacid)
- Rifampicin and Phenytoin: CYP 450 inducers
- calcium supplements and food
low
cholestyramine
lansoprazole
hyperthyroidism
- _____ disease
- toxic multinodular goiter (Plummer’s disease)
- toxic adenoma
- subacute thyroiditis: classical; postpartum
thyrotoxicosis:
- excessive heat
- increase _____ activity
- increase _____ sensitivity
- _____ eyes
- antiety
- avoid _____
graves sympathetic pain protruding epinephrine
hyperthyroidism
- non pharmacological management
- -adequate _____; _____ and rest (especially in the elderly)
- -subtotal/ total _____
- -patients with graves disease; toxic adenoma, toxic multinodular goitre
nutrition
hydration
thyroidectomy
hyperthyroidism pharmacological management: -\_\_\_\_\_: methimazole; propylthiouracil (PTU) -\_\_\_\_\_: complex anion/ potent inhibitor of iodide transport. it is the \_\_\_\_\_ product of \_\_\_\_\_ and can easily be measured in body fluids -iodine (potassium iodide) -radioactive iodine (131I) --except \_\_\_\_\_ during pregnancy -beta blockers
thioamines thiocyanate detoxification cyanide subacute thyroiditis
hyperthyroidism: drug management
thioamides:
methimazole (tapazole); propylthiouracil [PTU] (prophylthiour)
indicated for hyperthyroid patients except in _____
- MOA:
- -_____ T4 and T3 production/ synthesis
- -decrease the conversion of _____ to _____
- adverse effects:
- -maculopapular pruritic rash +/- fever
- vasculitis, arthralgia
- _____-like reaction
subacute thyroiditis decrease T4 T3 lupus
