— 生理適應 · MEDIUM · MCQ —
下列哪項老人常見的生理改變會影響藥物代謝？
Which of the following is an expected physiological change in the elderly that impacts drug metabolism?
- AIncreased hepatic blood flow肝臟血流增加
- BIncreased muscle mass肌肉質量增加
- CDecreased glomerular filtration rate✓ 正解腎絲球過濾率下降
- DIncreased gastric emptying胃排空速度增加
— Explanation · 中文詳解 —
老人隨著年齡增長，腎臟生理結構會發生退化，包括腎單位（Nephron）數量減少與腎血流量下降，導致腎絲球過濾率（GFR）下降。這直接影響藥物的排除速率，使得經腎臟代謝的藥物在體內半衰期延長，極易造成血中濃度過高而引發毒性反應。因此，老年人用藥需遵循「Start low, go slow」原則，並密切監測腎功能指標（如肌酸酐清除率）。
Aging causes degenerative changes in renal structure, including reduced nephron count and blood flow, which leads to a decreased glomerular filtration rate (GFR). This reduction slows the clearance of renally excreted drugs, prolonging their half-life and increasing the risk of toxicity, necessitating cautious dosing strategies in older adults.