AANP Family Nurse Practitioner (FNP) Certification ExamEvaluationMedium
A 50-year-old female with newly diagnosed hypothyroidism is started on levothyroxine 50 mcg daily. She returns for follow-up in 6 weeks. Her TSH is 8.2 mIU/L (reference range 0.4-4.0 mIU/L), and she reports persistent fatigue and weight gain. Which adjustment to her medication is most appropriate?
- AIncrease levothyroxine to 75 mcg daily.
- BSwitch to a desiccated thyroid extract.
- CAdd liothyronine (T3) to her current regimen.
- DMaintain current levothyroxine dose and recheck TSH in 3 months.
Show answer & explanationAnswer & explanation
Correct answer: A. Increase levothyroxine to 75 mcg daily.
The patient's TSH remains elevated above the target range, indicating that her current levothyroxine dose is insufficient to adequately replace thyroid hormone. The most appropriate next step is to increase the levothyroxine dose and recheck TSH in approximately 6 weeks to assess the response.
Why the other options are wrong
- B. Switching to desiccated thyroid extract is a less common and often more complex option, not typically indicated as a first-line adjustment when levothyroxine alone is not yet optimized.
- C. Adding liothyronine (T3) is generally reserved for specific cases and is not a first-line adjustment for primary hypothyroidism with an elevated TSH on initial levothyroxine therapy.
- D. Maintaining the current dose is inappropriate as the TSH is still significantly elevated, and symptoms persist, indicating the need for dose adjustment.
Levothyroxine Dose Adjustment
Levothyroxine dosage is adjusted based on TSH levels, aiming to normalize TSH within the reference range (0.4-4.0 mIU/L) and alleviate symptoms.
- TSH is the primary monitoring parameter for hypothyroidism.
- Dose adjustments are typically made in 12.5-25 mcg increments.
- Recheck TSH 6-8 weeks after any dose change.
Memory trick: TSH is high, dose must fly!