Report chest pain, palpitations, or tachycardia (over-replacement).
Before you read
Test yourself first: 5 questions
Question 1 of 5
A client newly prescribed levothyroxine for hypothyroidism asks how to take it. Which instruction is correct?
Answer: B. Levothyroxine is best absorbed on an empty stomach. Take it in the morning at least 30 to 60 minutes before breakfast, with water, and separated from calcium, iron, and antacids, which impair absorption. It is a lifelong daily medication and should not be stopped when symptoms improve.
Question 2 of 5
A client starting levothyroxine for hypothyroidism is taught to take it:
Answer: B. Take levothyroxine in the morning on an empty stomach, ~30–60 minutes before breakfast, consistently, and not with calcium/iron or antacids. It is lifelong; don't stop when feeling better.
Question 3 of 5
A client who takes levothyroxine reports palpitations, heat intolerance, weight loss, and difficulty sleeping. Which interpretation by the nurse is correct?
Answer: B. These are signs of hyperthyroidism, suggesting the levothyroxine dose is too high (overreplacement). The provider should be notified, as the dose likely needs to be reduced. These findings are not signs of hypothyroidism or an allergic reaction and do not indicate the dose is too low.
Question 4 of 5
A nurse is caring for a client taking levothyroxine who is scheduled to start the medication. Which client history finding requires the nurse to consult the provider before administering the first dose?
Answer: B. Levothyroxine increases metabolic demand and heart rate and can precipitate angina, dysrhythmias, or myocardial infarction in clients with cardiac disease; such clients are started on lower doses and titrated slowly. A history of coronary artery disease should be reported before the first dose. Mild seasonal allergies, a remote appendectomy, and well-controlled hypertension are less immediately concerning for thyroid replacement initiation.
Question 5 of 5
A client is taking levothyroxine for hypothyroidism. Which instruction should the nurse include in the teaching?
Answer: B. Levothyroxine should be taken in the morning on an empty stomach, ideally 30 to 60 minutes before breakfast, with water, and taken consistently at the same time daily. Food and certain products (calcium, iron, antacids) reduce absorption. It is a lifelong replacement, not stopped when symptoms improve.
Keep the streak going with more questions like these, each with a full rationale.
What is levothyroxine?
It restores normal metabolism, energy, and body temperature. Key principle: it is a lifelong, once-daily medication taken on an empty stomach, and effects take weeks to appear.
Key points to remember
- It is taken once daily in the morning on an empty stomach, 30-60 minutes before food.
- Full therapeutic effect takes several weeks; doses are titrated to TSH levels.
- Signs of overdose mimic hyperthyroidism: tachycardia, weight loss, heat intolerance, and tremor.
- It increases the effect of warfarin and may increase insulin or oral hypoglycemic needs.
- Antacids, calcium, and iron decrease its absorption and should be separated by 4 hours.
Nursing priorities
- Monitor TSH and free T4 to guide dosing.
- Assess heart rate before administration and report tachycardia or palpitations.
- Evaluate for symptom improvement: energy, weight, and bowel function.
- Teach lifelong, consistent timing on an empty stomach.
- Monitor for chest pain in older adults or those with cardiac disease.
Labs & values
Patient teaching
- Take on an empty stomach with water, same time every morning.
- Do not switch brands without provider approval.
- Report rapid heartbeat, chest pain, or excessive nervousness; effects take weeks.
Red flags: report now
- Report chest pain, palpitations, or tachycardia (over-replacement).
- Never stop abruptly; it is a lifelong therapy.
- Report signs of hyperthyroidism: insomnia, tremor, and heat intolerance.
References
Clinical references for this topic
