頭孢泊肟酯 (Cefpodoxime Proxetil)
**頭孢泊肟酯 (Cefpodoxime proxetil)** 是一種口服第三代頭孢菌素類抗生素，主要用於獸醫學中治療敏感細菌感染，特別是犬隻的皮膚感染。 * **前驅藥劑型**：酯化的「proxetil」成分能提高脂溶性與腸胃道吸收率。吸收後，它會在腸壁迅速水解為具活性的代謝物頭孢泊肟。 * **抗菌譜**：對多種革蘭氏陽性菌（如假中間葡萄球菌、金黃色葡萄球菌和犬鏈球菌）及革蘭氏陰性腸桿菌科（如大腸桿菌、奇異變形桿菌、多殺性巴斯德桿菌和克雷伯氏菌）非常有效。 * **臨床要點**：它對綠膿桿菌、腸球菌屬、厭氧菌或抗甲氧西林葡萄球菌 (MRSA/MRSP) 無效。在犬隻中每日一次的給藥頻率能顯著提高飼主的順從性，優於如頭孢氨苄等第一代頭孢菌素。
作用機制: Cefpodoxime is a **bactericidal** antibiotic that disrupts bacterial cell wall synthesis. * It binds to specific **Penicillin-Binding Proteins (PBPs)** located inside the bacterial cell wall. * Inhibition of PBPs → prevents the cross-linking of peptidoglycan chains → weakens the bacterial cell wall. * This structural instability → osmotic pressure changes → **cell lysis** and death. * As a third-generation cephalosporin, it exhibits increased stability against many bacterial **beta-lactamase** enzymes compared to earlier generations.
各物種劑量
- For susceptible skin and soft tissue infections · 5 mg/kg PO q12h or 10 mg/kg PO once daily · PO · q12h or q24h · Extrapolated from human dosage.
- Foals (neonates) with bacterial infections · 10 mg/kg PO q6-12 hours · PO · q6-12h · Additional studies required to confirm clinical efficacy and safety.
- For susceptible skin infections · 5-10 mg/kg PO once daily · PO · q24h · 5-7 days or 2-3 days beyond cessation of clinical signs, up to a maximum of 28 days. Treatment of acute infections should not be continued for more than 3-4 days if no response to therapy is seen. · May be given with or without food.
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
- Hypersensitivity to cefpodoxime or other cephalosporins
不良反應
- Inappetence
- Diarrhea
- Vomiting
- Hypersensitivity reactions
- Positive direct Coombs' test
- Blood dyscrasias (rare, following high doses)
藥物相互作用
- Aminoglycosides / Nephrotoxic drugs (e.g., amphotericin B) · Potentially additive nephrotoxicity (controversial). In vitro synergy exists, but do not mix together in the same syringe/fluid.
- Antacids · Drugs that increase stomach pH may decrease the absorption of cefpodoxime.
- H-2 Antagonists (ranitidine, famotidine) · Drugs that increase stomach pH may decrease the absorption of cefpodoxime.
- Probenecid · Competitively blocks tubular secretion of cephalosporins, increasing serum levels and half-lives.
- Proton Pump Inhibitors (omeprazole) · Drugs that increase stomach pH may decrease the absorption of cefpodoxime.
監測
- Clinical efficacy (resolution of infection)
- Adverse GI effects
過量
Cephalosporin overdoses are unlikely to cause significant problems. The most likely signs of acute toxicity or overdose are gastrointestinal disturbances (vomiting, diarrhea, inappetence). Supportive care should be provided if necessary.
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。