頭孢西丁
Cefoxitin
Cefoxitin sodium
別名: Mefoxin · Mefoxitin · Cefociclin · Cefoxin · MK-306 · L-620-388 · cefoxitinum · cefoxitina · cefoxitine
由 VetSheet 獸醫團隊審訂更新於 2026年4月5日本內容以實證獸醫文獻為本
劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。
各物種劑量
🌎 NA — North America🌍 EU — Europe
狗
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Mixed infections (e.g., aspiration pneumonia, bowel perforation) | 30 mg/kg SC q8h; 30 mg/kg IV q4-6h | SC/IV | q8h or q4-6h | — | 🌎 NA |
| Sepsis | 30 mg/kg IV q5h | IV | q5h | — | 🌎 NA |
| Soft tissue infections | 30 mg/kg SC q8h or 30 mg/kg IV q5h | SC/IV | q8h or q5h | — | 🌎 NA |
| Bacteremia | 15-30 mg/kg IV, IM SC q6-8h | IV/IM/SC | q6-8h | — | 🌎 NA |
| Orthopedic infections | 22 mg/kg IV, IM q6-8h | IV/IM | q6-8h | Use as long as necessary to control initial infection, then switch to oral drugs | 🌎 NA |
| Susceptible infections | 30 mg/kg SC q8h | SC | q8h | — | 🌎 NA |
貓
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Systemic infections | 25-30 mg/kg IV or IM q8h | IV/IM | q8h | Use as long as necessary to control initial infection, then switch to oral drugs | 🌎 NA |
| Sepsis | 30 mg/kg IV q5h | IV | q5h | — | 🌎 NA |
| Susceptible infections | 30 mg/kg IV q8h | IV | q8h | — | 🌎 NA |
| Non-tuberculosis mycobacteria (NTM) - second line treatment | 30-40 mg/kg IV, IM or SC q6-8h | IV/IM/SC | q6-8h | — | 🌎 NA |
- Non-tuberculosis mycobacteria (NTM) - second line treatment: Causes pain on injection with IM or SC
馬
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Susceptible infections (Foals) | 20 mg/kg IV q4-6h | IV | q4-6h | — | 🌎 NA |
劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。
概覽
頭孢西丁是一種第二代注射用頭孢菌素（嚴格來說屬於頭黴素類），在獸醫學中用於治療嚴重或混合性細菌感染。
主要藥理特點包括：
- 抗厭氧菌效力：與許多早期頭孢菌素不同，頭孢西丁對厭氧菌（包括脆弱擬桿菌 Bacteroides fragilis）具有極佳的抗菌效果。
- 革蘭氏陰性菌抗菌譜：對許多可能對第一代藥物產生抗藥性的大腸桿菌 (E. coli)、克雷伯氏菌 (Klebsiella) 和變形桿菌 (Proteus) 菌株具有良好的活性。
- 革蘭氏陽性菌抗菌譜：保留了對革蘭氏陽性球菌的活性，儘管在同等劑量下其效力略低於第一代頭孢菌素。
臨床要點：由於其強大的抗厭氧菌抗菌譜，頭孢西丁經常被選用於治療混合感染，如吸入性肺炎、腸穿孔以及嚴重的軟組織感染或敗血症。
作用機轉
Cefoxitin is a bactericidal antibiotic that works by inhibiting bacterial cell wall synthesis.
- It covalently binds to specific Penicillin-Binding Proteins (PBPs) located inside the bacterial cell wall.
- Binding to PBPs → inhibits the transpeptidation enzyme responsible for cross-linking peptidoglycan strands.
- Lack of cross-linking → weakens the bacterial cell wall → leads to osmotic instability, cell lysis, and bacterial death.
- As a cephamycin, cefoxitin is highly resistant to degradation by many beta-lactamases, particularly those produced by Bacteroides species.
安全性與警告
禁忌症
- Patients with a history of hypersensitivity to cephalosporins
- Use with extreme caution in patients documented to be hypersensitive to other beta-lactams (penicillins, carbapenems)
不良反應
- Hypersensitivity reactions (rashes, fever, eosinophilia, lymphadenopathy, anaphylaxis)
- Pain at the injection site (IM)
- Sterile abscesses or local tissue reactions
- Thrombophlebitis (IV administration)
- Antibiotic-associated diarrhea or altered gut flora
- Superinfections
- Nephrotoxicity (rare at clinical doses)
- Neurotoxicity, neutropenia, thrombocytopenia, hepatitis (associated with high doses or prolonged use)
注意事項
Important Precautions
- Renal Impairment: Patients in renal failure may require dosage adjustments as the drug is primarily eliminated via the kidneys.
- Cross-Reactivity: Cross-hypersensitivity with penicillins can occur (estimated 1-15% in humans; unknown in veterinary species).
- Administration: Causes pain on IM injection. When giving IV, administer slowly over 3-5 minutes or more to minimize adverse reactions.
- Laboratory Interference: May cause false-positive urine glucose tests (cupric sulfate method) and falsely elevated serum/urine creatinine values (Jaffe reaction).
藥物交互作用
Potential for additive nephrotoxicity. While in vitro synergy exists against certain bacteria, they should not be mixed in the same syringe or fluid bag.
Competitively blocks the tubular secretion of cefoxitin, thereby increasing serum levels and prolonging elimination half-lives.
監測
- Clinical efficacy (resolution of infection signs)
- Renal function (BUN, creatinine, urinalysis) in patients with diminished renal capacity
藥物動力學
半衰期
吸收
Not appreciably absorbed after oral administration; must be given parenterally to achieve therapeutic serum levels.
分佈
Widely distributed. In horses, Vd at steady state is 110 mL/kg. In calves, Vd is 318 mL/kg and it is ~50% protein bound. Crosses the placenta and distributes into milk in low concentrations.
代謝
Minimal. In humans, approximately 2% of a dose is metabolized to inactive descarbamylcefoxitin.
排除
Primarily excreted unchanged by the kidneys into the urine via both tubular secretion and glomerular filtration. Elimination is significantly prolonged in severe renal failure.
過量
Acute oral cephalosporin overdoses are unlikely to cause significant problems other than gastrointestinal distress.
Massive parenteral overdoses or prolonged accumulation (especially in renal failure) may lead to:
- Neurotoxicity (seizures)
- Neutropenia or thrombocytopenia
- Hepatitis
- Nephrotoxicity (tubular necrosis)
Treatment is supportive and symptomatic.
可用產品
劑型
- Powder for injection
人用標示
- Cefoxitin Sodium Powder for Injection: 1 g, 2 g, & 10 g in vials & infusion bottles
各地核准狀態
暫無法規資料: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Store powder for injection < 30°C; do not expose to > 50°C. Frozen solutions should be stored <= -20°C. After reconstitution, stable for 24 hours at room temperature and 48 hours to 1 week if refrigerated. If immediately frozen after reconstitution, stable up to 30 weeks at -20°C. Darkening of the powder/solution does not affect potency.
飼主須知
頭孢西丁是一種強效的注射型抗生素，通常由獸醫專業人員在診所或醫院環境中給藥，用於治療嚴重或複雜的感染。
- 給藥方式：由於它是透過注射給藥，您通常不需要在家中操作。如果您的寵物接受皮下 (SC) 或肌肉 (IM) 注射，注射部位可能會出現暫時性的疼痛或腫脹。
- 副作用：雖然通常非常安全，但有些寵物可能會出現輕微的腹瀉或腸胃不適。
- 過敏反應：如果您的寵物曾對青黴素或其他抗生素有過敏反應，或者在治療期間發現任何過敏跡象（如臉部腫脹、蕁麻疹、呼吸困難），請立即通知您的獸醫。
VetSheet 藥物參考供合格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商最新仿單。