- Body system
- Endocrine
- Brand names
- Synthroid, Levoxyl, Unithroid, Euthyrox, Tirosint
What is Levothyroxine used for?
- Hypothyroidism
- TSH suppression in some thyroid cancers
- Myxedema coma (IV)
How Levothyroxine works
Synthetic T4 thyroid hormone: replaces the hormone the thyroid gland does not make.
Common side effects
- Usually none at the right dose
- Too much: palpitations, tachycardia, nervousness, insomnia, heat intolerance, weight loss
Report right away
- Chest pain, fast or irregular heartbeat
- Tremor, sweating, insomnia, diarrhea
Nursing considerations for Levothyroxine
- Monitor TSH; dose changes are judged after about 6 to 8 weeks.
- Start low in older adults and in coronary artery disease: it raises the heart's oxygen demand.
- Many products bind it: separate from calcium, iron, antacids and some other drugs by about 4 hours.
Patient teaching
- Take it once a day on an empty stomach, 30 to 60 minutes before breakfast, with a full glass of water.
- This is usually lifelong therapy; do not stop it when you feel better.
- Do not switch brands or generics without telling your provider.
This card does not list doses. Use the prescriber's order, the product label and a current drug reference for dosing, and follow your facility's policies.
Thyroid and antithyroid drugs practice questions
NCLEX-style questions on the class Levothyroxine belongs to.
3 questions. Choose an answer to see the rationale.
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When should a patient take levothyroxine?
Show answer
Answer B: On an empty stomach 30 to 60 minutes before breakfast Food, calcium and iron reduce absorption. Taking it consistently on an empty stomach gives stable levels.
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A patient taking methimazole reports fever and a sore throat. What is the priority?
Show answer
Answer C: Notify the provider and check the CBC: possible agranulocytosis Agranulocytosis is a serious adverse effect of thioamides; fever and sore throat are the warning signs.
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Which finding suggests the levothyroxine dose is too high?
Show answer
Answer A: Palpitations and insomnia Too much thyroid hormone causes signs of hyperthyroidism, such as palpitations, nervousness and insomnia.
Frequently asked questions
What is Levothyroxine used for?
Hypothyroidism; TSH suppression in some thyroid cancers; Myxedema coma (IV).
What drug class is Levothyroxine?
Levothyroxine belongs to the class thyroid and antithyroid drugs. Synthetic T4 thyroid hormone: replaces the hormone the thyroid gland does not make.
What are the nursing considerations for Levothyroxine?
Monitor TSH; dose changes are judged after about 6 to 8 weeks. Start low in older adults and in coronary artery disease: it raises the heart's oxygen demand.
What should patients report while taking Levothyroxine?
chest pain, fast or irregular heartbeat; tremor, sweating, insomnia, diarrhea.