Chapter 61 - Drugs for Thyroid Disorders Flashcards
What do thyroid hormones effect?
-metabolism
-cardiac function
-growth
-development
What is the role of the parathyroid gland?
maintaining calcium fluid in the ECF
What induces thyroid hormone synthesis?
low plasma levels of iodine
What drug mimics T3 (triiodothyronine)?
liothyronine
What drug mimics thyroxine (T4)?
levothyroxine
The serum TSH test is used to screen and diagnose for ____________?
hypothyroidism
Elevates TSH indicates ____________
hypothyroidism
What is the preferred measure to monitor thyroid replacement drugs?
serum TSH
What does the serum T4 test measure?
total T4 or free T4
What is the preferred measure for hyperthyroidism?
serum T3 test (total and free)
Myxedema is a form of ______thyroidism in _______
hypo; adults
What is the treatment for myxedema?
lifelong (usually) replacement hormone therapy
What condition is responsible for hypothyroidism during pregnancy?
myxedema
Cretinism is a type of _______thyroidism in _______
hypo; infancy
How does hypothyroidism present in adults?
-pale, puffy face
-cold, dry skin
-hair loss
-lowered HR
-low temp.
-fatigue
-intolerance to cold
-impaired mentality
What can cause hypothyroidism in adults?
-thyroid malfunction
-Hashimoto’s disease
-insufficient iodine in diet
-thyroid removal
-insufficient TSH and TRH
What drugs are used for hypothyroidism?
-levothyroxine (most common) T4
-liothyronine T3
How can hypothyroidism affect pregnancy?
cause neuropsychologic deficits in the child
How can cretinism affect infants?
-intellectual disability
-growth deficit
Graves’ disease is a form of _______thyroidism
hyper
What is the most common form of hyperthyroidism?
Graves’ disease
Toxic nodular goiter aka Plummer’s disease is a form of ______thyroidism
hyper
What is the cause of Grave’s disease?
thyroid-stimulating immunoglobulins (autoimmune antibodies)
What is the treatment of Grave’s disease?
-surgical removal
-TSH suppression
-beta blockers
-nonradioactive iodine
What causes thyrotoxic crisis (thyroid storm)?
-stress
-not rise in TH’s
-not identified in lab testing
What are the signs of thyroid storm?
-hyperthermia
-severe tachycardia
-restlessness
-agitation
-tremor
-coma
-hypotension
-HF
What is the treatment for thyroid storm?
-methimazole
-beta blocker
-sedation
-cooling
-glucocorticoids
-IV fluids
What is levothyroxine?
a synthetic form of thyroxine (T4) that is converted to T3 in the body
What is levothyroxine used for?
hypothyroidism
When is levothyroxine taken?
in the morning - 30-60 mins before breakfast
What are the adverse effects of levothyroxine?
-tachycardia
-angina
-tremors
When do peak effects of levothyroxine occur?
3-4 weeks
How long do the effects of levothyroxine last?
1-3 weeks but dosed daily
How does levothyroxine travel in the blood?
99% protein bound
How long does levothyroxine remain in the blood after discontinuation?
3 weeks
What is methimazole used for?
hyperthyroidism
How does methimazole act?
blocks synthesis of thyroid hormones
Does methimazole cross the placenta?
yes
Is methimazole used during pregnancy?
no
How long does it take for methimazole to take effect?
3-12 weeks
What are the adverse effects of methimazole?
-agranulocytosis
-hypothyroidism
-skin rash
-muscle aches
-abnormal taste/smell
What is the blood work needed for methimazole?
-hepatic
-renal
-CBC
-TSH
What are the possible complications of propylthiouracil (for hyperthyroidism)?
-risk of liver failure
-agranulocytosis
Nursing implications of anti-thyroid meds:
-better tolerated with food
-take at same time each day
-don’t stop abruptly
-avoid high iodine foods
What is radioactive iodine-131?
a radioactive isotope of stable iodine
What does 131I emit?
gamma and beta rays
How long does it take for 131I to take full effect?
2-3 months
When is 131I used?
grave’s disease to destroy thyroid tissue
When is 131I used?
with no response to meds
When is 131I not used?
pregnancy and lactation
