萬古黴素
**萬古黴素 (Vancomycin)** 是一種強效的殺菌性糖肽類抗生素，在人類和獸醫學中傳統上被視為「最後一線藥物」。 * **臨床作用：** 嚴格保留用於治療由多重耐藥革蘭氏陽性菌引起的嚴重、危及生命的感染，例如**耐甲氧西林金黃色葡萄球菌 (MRSA)**、**耐甲氧西林偽中間葡萄球菌 (MRSP)** 以及多重耐藥的腸球菌。 * **給藥方式：** 對於全身性感染，**必須**以緩慢靜脈輸注 (IV) 的方式給藥。嚴禁皮下 (SC) 或肌肉 (IM) 注射，因為會導致嚴重的組織壞死和疼痛。 * **口服使用：** 由於萬古黴素不會透過胃腸道吸收，口服給藥專門用於治療嚴重的局部腸道感染，特別是由**困難梭狀芽孢桿菌 (*Clostridium difficile*) 引起的偽膜性腸炎**。 > **臨床要點：** 由於萬古黴素在治療人類致命感染中具有至關重要的地位，其在獸醫學中的使用極具爭議，只有在細菌培養和藥敏試驗證實沒有其他可行的抗生素選擇時才應考慮使用。
作用機制: Vancomycin exerts its bactericidal effect primarily by inhibiting bacterial cell wall synthesis. * **Target Binding:** It binds tightly and non-covalently to the **D-alanyl-D-alanine** terminus of cell wall precursor units. * **Inhibition:** This massive steric hindrance prevents the enzymes (transglycosylases and transpeptidases) from incorporating the precursors into the growing peptidoglycan matrix → **inhibition of cell wall cross-linking**. * **Secondary Mechanisms:** It also alters bacterial cell-membrane permeability and interferes with RNA synthesis, making resistance more difficult to develop. * **Spectrum:** Activity is strictly limited to **gram-positive** organisms (staphylococci, streptococci, enterococci, *Clostridium*, *Listeria*). It is bactericidal against most susceptible bacteria but generally bacteriostatic against enterococci.
各物種劑量
- Confirmed bacteremia/septicemia for enterococci or staphylococci resistant to other commonly used antibiotics · 15 mg/kg IV over 30-60 minutes · IV · q6-8h
- Serious infections · 15 mg/kg IV over 30-60 minutes · IV · q6h · For successful therapy, an aminoglycoside such as gentamicin or amikacin should also be administered.
- Confirmed bacteremia/septicemia for enterococci or staphylococci resistant to other commonly used antibiotics · 15 mg/kg IV over 30-60 minutes · IV · q6-8h
- Serious infections · 15 mg/kg IV over 30-60 minutes · IV · q6h · For successful therapy, an aminoglycoside such as gentamicin or amikacin should also be administered.
- C. difficile enterocolitis · 10-20 mg/kg PO · PO · q6h · 5-7 days · Oral vancomycin is not appreciably absorbed and is only effective for susceptible enteric infections.
- Skin, urinary, soft tissue infections · 10-20 mg/kg IV · IV · q12h · 7-10 days
- Systemic infections, bacteremia · 15 mg/kg IV · IV · q6h · 10 days
劑量為合格獸醫專業人員的臨床參考。請務必對照最新藥品仿單及個別病患確認。
給藥途徑
禁忌症
- Infections susceptible to other, lower-tier antibiotics
- Intramuscular (IM), Subcutaneous (SC), or Intraperitoneal (IP) administration
- Rapid IV bolus administration
不良反應
- Nephrotoxicity (especially with concurrent nephrotoxic drugs)
- Ototoxicity (hearing loss/vestibular signs)
- Thrombophlebitis (if given IV too rapidly)
- Severe hypotension or cardiac arrest (rare, associated with rapid IV bolus)
- Severe tissue damage and pain (if given IM, SC, or IP)
- Nausea and inappetence (with oral administration)
- Reversible neutropenia (with high/prolonged dosing)
- Hypersensitivity/dermatologic reactions (known in humans as 'Red Man Syndrome' due to histamine release)
藥物相互作用
- Aminoglycosides (e.g., gentamicin, amikacin) · Synergistic antibacterial effect, but significantly increases the risk of ototoxicity and nephrotoxicity. Enhanced monitoring is required.
- Anesthetic agents · May cause erythema and histamine-like flushing (reported in human pediatric patients).
- Nephrotoxic drugs (e.g., amphotericin B, cisplatin) · Increased risk of severe nephrotoxicity; use together with extreme caution.
監測
- Renal function (BUN, Creatinine, Urinalysis) at baseline and periodically during treatment
- Vancomycin serum trough levels (maintain above 5 mcg/mL; some specialists recommend 10-15 mcg/mL)
- Periodic Complete Blood Count (CBC) if therapy is prolonged (to monitor for neutropenia)
- Hearing and vestibular function (clinical observation)
過量
Patients with severe colitis taking an oral overdose could potentially absorb enough drug to cause systemic adverse effects. Intravenous overdoses significantly increase the risk of **ototoxicity** (hearing/balance damage) and **nephrotoxicity** (kidney damage). * **Toxicity Data:** The IV LD50 in mice is 400 mg/kg and in rats is 319 mg/kg. * **Treatment:** Treatment is primarily supportive care. Hemodialysis does not appear to remove the drug in significant amounts.
VetSheet 藥物參考供持牌獸醫專業人員作臨床決策輔助之用,不能取代專業判斷或廠方最新藥品說明書。