Thyroid Disorders USMLE Step 1 Practice Question
A 55-year-old woman with hypothyroidism on levothyroxine 75 mcg daily presents with persistent fatigue and weight gain. Vital signs: BP 128/82, HR 58, RR 14, Temp 36.8°C. TSH is elevated at 8.2 mIU/L despite medication adherence. Free T4 is low-normal at 0.8 ng/dL. She denies dyspnea or palpitations. Recently, she started taking calcium supplements and a multivitamin for bone health. Which over-the-counter agent is most likely impairing her levothyroxine absorption?
Answer choices
- APropylthiouracil
- BTolvaptan
- CDesmopressin
- DOctreotide
- EFerrous sulfateCorrect answer
- FAluminum hydroxide
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