Thyroid Flashcards
What hormone controls production and release of thyroid hormones?
Thyroid-stimulating hormone (TSH)
A child is diagnosed with hypothyroidism. The nurse anticipates an order for the drug of choice when treating children, which is what?
Levothyroxine (Synthroid)
The nurse is providing patient teaching regarding the administration of levothyroxine (Synthroid). What is the nurses priority teaching point?
- Take the medication with a full glass of water
- The medication should be taken on an empty stomach before breakfast
Methimazole (Tapazole) is used to treat:
hyperthyroidism
Important lab monitoring for Methimazole:
Regular labs to monitor for bone marrow suppression, which can be an adverse effect
What assessment findings would the nurse expect to see in a patient who overdosed on levothyroxine (Synthroid)?
Nervousness, tachycardia, tremors
After administering propylthiouracil (PTU), what effect would the nurse anticipate the drug will have in the patients body?
To inhibit production of thyroid hormone in the thyroid gland
In patients taking levothyroxine; what lab results would indicate a need for drug increase?
Elevated TSH, reduced T3 and T4 levels: TSH levels would be elevated to stimulate increased thyroid hormone secretion whereas T4 and T3 will be low
The nurse is caring for a patient newly diagnosed with hypothyroidism. The patient also takes theophylline to control asthma symptoms. What changes will need to be made to the patients theophylline dose?
Increase theophylline dosage immediately:
Rationale: Theophylline clearance is decreased in hypothyroid states. As the patient approaches normal thyroid function, theophylline dose may need to be adjusted frequently
The patient is 8 weeks pregnant and requires an antithyroid medication. The nurse identifies what drug as the drug of choice for this patient?
Propylthiouracil (PTU) because it is less likely to cross the placenta and cause problems for the fetus
What signs/symptoms should the provider educate a patient who’s taking thyroid supplementation:
- Increased pulse rate; teach how to measure pulse (if greater than 100bpm at rest- dose should be withheld)
- nervousness
- chest pain,
- HTN
- unexplained weight loss of more than 2 pounds in 1 week
Drug interactions with thyroid replacements:
- Avoid concurrent use of TCA’s
- Calcium and iron supplements should be taken 2 to 4 hours before or after the hormone
If a dose of a thyroid replacement (synthroid) is missed, the patient should:
Take the dose as soon as it is remembered, if 4 hours after eating. If more than three doses are missed, the health-care provider should be informed.
If a patient changes brand of thyroid supplement medications, the provider should:
Monitor the patient’s TSH levels and titrate new drug over several months; advise patient NOT to change brands
Contraindications for the use of thyroid replacements:
Recent MI; they increase risk of cardiovascular events
True or false
Thyroid replacements can be used with women that have osteoporis
True, BUT provider should use lowest dose possible as thyroid replacements may exacerbate bone loss
ADR’s for thyroid replacement drugs:
- increased heart rate
- cardiac arrhythmias
- chest pain
- tremors/nervousness
- insomnia
- weight loss
- menstrual irregularities
- heat intolerance
What are the two drugs used for hyperthyroidism?
Propylthiouracil & Methimazole
How do hyperthyroidism drugs work? (MOA)
inhibit the synthesis of thyroid hormones
Propylthiouracil (PTU) is primarly metabolized by:
the liver with a significant first-pass effect
Out of the two hyperthyroid drugs, which one should be used first line-in pregnancy?
propylthiouracil; Methimazole is associated with birth defects
True or False
Both hyperthyroidism drugs cross the placenta during pregnancy
True. They both cross the placenta and can induce goiter and even cretinism in the fetus.
What is the most serious adverse reaction when using hyperthyroid drugs?
agranulocytosis and possible aplastic anemia
Blackbox warning for propylthiouracil:
Liver failure can occur; it should be reserved for those patients for whom surgery or methimazole is not appropriate
Drug interactions with propylthiouracil:
- lithium, potassium iodide, or sodium iodide: Additive antithyroid effects
- warfarin
Drug interactions with methimazole:
- Potassium iodide & amiodarone: decrease antithyroid effects
Drug interactions with both hyperthyroid drugs:
- Any drug that produces bone marrow depression causes additive bone marrow depression
- phenothiazines: increased risk of agranulocytosis
TSH levels should be evalutated:
Before beginning therapy, whenever symptoms recur, whenever dosages are adjusted, and every 2 to 3 months throughout therapy
What symptoms should patient be taught when reporting signs of agranulocytois:
sore throat, fever, chills, rash, and unusual bleeding or bruising
After starting methimazole it may take up to _ to _ months to see a total reversal of hyperthyroid symptoms:
6-12 months
A woman who is pregnant and has hyperthyroidism is best managed by a specialty team who will most likely treat her with:
Propylthiouracil (PTU)
- When starting a patient on levothyroxine for hypothyroidism the patient will need follow-up measurement of thyroid function in:
4 weeks
Treatment of a patient with hypothyroidism and cardiovascular disease consists of:
Levothyroxine
When starting a patient with hypothyroidism on thyroid replacement hormones patient education would include:
It may take 4 to 8 weeks to get to euthyroid symptomatically and by laboratory
testing.
In hyperthyroid states, what organ system other than CV must be evaluated to establish potential adverse issues?
The eye
What happens to the typical hormone replacement dose when a woman becomes pregnant?
The average woman needs more medication during pregnancy.
