護理師正給予萬古黴素（vancomycin）的靜脈輸注。病人同時也在服用呋塞米（furosemide）。護理師應對哪個潛在的副作用最為警惕？
A nurse is administering an IV infusion of vancomycin. The client is also taking furosemide. The nurse should be most alert for which potential adverse effect?
- AHypotension低血壓
- BHypokalemia✓ 正解低血鉀
- CHyperkalemia高血鉀
- DHypertension高血壓
Vancomycin 與 furosemide 併用最重要的協同風險為「耳毒性（ototoxicity）」與「腎毒性（nephrotoxicity）」——兩種藥物各自具有此類風險，併用時加成放大；實際臨床上需特別監測腎功能（BUN/Cr）與聽力。然而本題提供的選項中沒有這兩項，現有選項中以「低血鉀」(B) 最相關：furosemide 為 loop diuretic 會增加 K+ 排出，而電解質失衡會放大 vancomycin 在腎臟與心律方面的風險。其他選項：C 高血鉀並非 furosemide 典型效應；C 低血壓可能但不是兩藥組合最典型；D 高血壓非預期。
Vancomycin and furosemide each carry nephrotoxic and ototoxic risk; combining them magnifies these concerns. Among the answer options provided, hypokalemia is the most directly relevant because furosemide promotes urinary potassium loss, and the resulting electrolyte imbalance can amplify vancomycin's renal and cardiac risks. Hyperkalemia is not typical of loop diuretics; hypotension is possible but secondary; hypertension is not expected.