一位 65 歲病人因右心衰竭引起的嚴重周邊水腫接受治療後準備出院。他檢視居家處方時，發現醫師開立了兩種不同的利尿劑：furosemide（Lasix）與 spironolactone（Aldactone）。他問護理師：「同時吃兩種利尿劑不是弄錯了嗎？這樣不會把我體內的水都排光嗎？」哪項回應對這種組合提供了最正確的藥理學說明？
A 65-year-old client is preparing for discharge after treatment for severe peripheral edema secondary to right-sided heart failure. Reviewing his home prescriptions, he notices that his physician ordered two different diuretics: furosemide (Lasix) and spironolactone (Aldactone). He asks the nurse, "Isn't it an error to take two different water pills at the same time? Wouldn't that drain all the fluid out of me?" Which response provides the most accurate pharmacological reasoning for this combination?
- A"Spironolactone constricts your renal arteries so that the furosemide does not overwork your kidneys."「Spironolactone 會收縮您的腎動脈，讓 furosemide 不會使您的腎臟過度負荷。」
- B"This is a prescribing error; taking two potassium-wasting loop diuretics together can cause cardiac arrest."「這是處方錯誤；同時服用兩種會排鉀的環利尿劑可能導致心跳停止。」
- C"Furosemide only lowers your blood pressure, while spironolactone only pulls fluid out of your legs without affecting how much urine you make."「Furosemide 只會降低您的血壓，而 spironolactone 只會把您腿部的水分抽出來，不會影響您的尿量。」
- D"Furosemide causes your body to lose potassium, while spironolactone helps your body hold on to potassium. Taking them together removes the excess fluid while keeping your potassium level, and therefore your heart rhythm, stable."「Furosemide 會讓身體流失鉀，而 spironolactone 幫助身體保留鉀。兩者併用可以排除多餘的水分，同時維持您的血鉀濃度，也就維持了心律的穩定。」正確答案
- D「Furosemide 會讓身體流失鉀，而 spironolactone 幫助身體保留鉀。兩者併用可以排除多餘的水分，同時維持您的血鉀濃度，也就維持了心律的穩定。」
本題測驗心血管用藥中，利尿劑分類的協同作用。Furosemide (Lasix，環狀利尿劑) 是一種強效的「排鉀型（Potassium-wasting）」利尿劑。它能有效消除嚴重水腫，但同時會將鉀離子排出體外，極易引發致命的低血鉀（Hypokalemia）。而 Spironolactone (Aldactone) 是一種「保鉀型（Potassium-sparing）」利尿劑，透過拮抗醛固酮來排水，但會保留鉀離子（可能造成高血鉀）。在嚴重水腫且難治性心衰竭的病患中，醫師同時開立這兩種藥物並非錯誤，而是合理的用藥策略：能獲得加強的水分排出效益，同時藉由「排鉀對抗保鉀」的機制互相抵銷彼此對鉀離子的影響，藉此維持電解質平衡並保護心臟免於心律不整（選項 D 為正解）。選項 A 與 C 對兩種利尿劑的作用機理描述錯誤，無解剖與生理學依據。選項 B 錯誤，因為這兩者並非皆是排鉀利尿劑，一保一排。
- A「Spironolactone 會收縮您的腎動脈，讓 furosemide 不會使您的腎臟過度負荷。」
在沒有任何藥理學宇宙中，Spironolactone 會去收縮腎動脈以「掐住」Furosemide 的效能；事實上，它是作用在遠端小管來抑制醛固酮。
- B「這是處方錯誤；同時服用兩種會排鉀的環利尿劑可能導致心跳停止。」
充滿自信地診斷為處方錯誤誤導了病患。Spironolactone 明顯不是一種排鉀型環狀利尿劑，這抹除了致命對稱組合重疊的任何論點。
- C「Furosemide 只會降低您的血壓，而 spironolactone 只會把您腿部的水分抽出來，不會影響您的尿量。」
這兩種藥物都積極命令腎臟排出巨量的尿液。錯誤地陳述 Spironolactone 不直接影響尿量，嚴重誤解了它的利尿本質。
- D · 正確答案「Furosemide 會讓身體流失鉀，而 spironolactone 幫助身體保留鉀。兩者併用可以排除多餘的水分，同時維持您的血鉀濃度，也就維持了心律的穩定。」
這正確地將環狀利尿劑（Furosemide）的排鉀機制與 Spironolactone 的保鉀結構配對，達成巨大排水功效，同時優雅地防禦了威脅生命的低血鉀或高血鉀心律不整。
「Furosemide 排鉀 vs Spironolactone 保鉀」是藥理學國考最常出的送分對比題。這種「互補式雞尾酒處方」的知識，是護理師避免在病房亂填異常報告（以為醫師開出重複藥物）的必備常識。
English explanation
Option D is correct because furosemide is a potent potassium-wasting loop diuretic that effectively removes severe edema but can also cause substantial potassium loss and life-threatening hypokalemia. Spironolactone is a potassium-sparing diuretic that promotes fluid loss by antagonizing aldosterone while retaining potassium, although it can cause hyperkalemia. Combining them is a rational strategy for severe edema and refractory heart failure: it strengthens fluid removal while the potassium-wasting and potassium-sparing effects counterbalance each other, maintaining electrolyte balance and protecting the heart from dysrhythmias. Option A is incorrect because spironolactone does not protect the kidneys by constricting the renal arteries; this description has no anatomic or physiologic basis. Option B is incorrect because the drugs are not two potassium-wasting loop diuretics; one wastes potassium and the other spares it. Option C is incorrect because furosemide is not limited to lowering blood pressure, and spironolactone does affect urine production rather than selectively pulling fluid from the legs.
最近修訂：2026-10-05