護理師正在衛教病人服用左甲狀腺素（levothyroxine）。哪項指示是必須的？
A nurse is educating a client about taking levothyroxine. Which instruction is essential?
- ACrush the tablet and mix it with applesauce.將藥片壓碎並混合蘋果泥。
- BTake the medication with meals to improve absorption.隨餐服用藥物以促進吸收。
- CTake the medication at bedtime.睡前服用藥物。
- DTake the medication on an empty stomach, preferably in the morning.✓ 正解空腹服用藥物，最好是在早上。
左甲狀腺素（levothyroxine, T4）是甲狀腺機能低下症的標準替代治療藥物。其吸收受多種因素影響，正確服用方式攸關治療效果。 選項 D 正確：標準衛教為「空腹服用，最佳於早晨起床後立即服用，並等待 30-60 分鐘後再進食或喝咖啡」。空腹確保藥物吸收最大化（食物可降低吸收率達 40%）；早晨服用配合甲狀腺素的生理日節律。 選項 B 錯誤：食物（特別是高纖、鈣質、鐵質、咖啡）會干擾吸收。 選項 C 錯誤：睡前服用可能引起失眠（甲狀腺素具刺激作用），且夜間胃酸減少影響吸收。 選項 A 錯誤：除非有吞嚥困難並經醫師指示，levothyroxine 不應壓碎；混合食物會破壞吸收。長期吸收不穩定可能導致甲狀腺素濃度波動。
Levothyroxine (T4) is the standard replacement therapy for hypothyroidism. Its absorption is sensitive to several factors, making proper administration critical for efficacy. D is correct: Standard teaching is to take on an empty stomach, ideally first thing in the morning, and wait 30-60 minutes before eating or drinking coffee. Empty stomach maximizes absorption (food can reduce absorption by up to 40%); morning timing aligns with thyroid hormone circadian rhythm. B is incorrect: Food (especially high-fiber, calcium, iron, coffee) interferes with absorption. C is incorrect: Bedtime dosing may cause insomnia from the stimulant effect, and gastric acid is lower at night, affecting absorption. A is incorrect: Tablets should not be crushed unless specifically ordered for swallowing difficulty; mixing with food disrupts absorption and may cause fluctuating thyroid hormone levels.
美國的內分泌學會提供詳細的藥物服用指引，包括左甲狀腺素的服用時間與交互作用；台灣的衛教手冊也強調空腹服用，但細節可能因醫療機構而異。