頭孢噻呋鹽酸鹽
頭孢噻呋鹽酸鹽 (Ceftiofur HCl) 是一種**獸醫專用的第三代頭孢菌素**抗生素。主要應用於大型動物醫學（特別是豬和牛），用於治療細菌性呼吸道疾病、腐蹄病、急性子宮內膜炎和乳腺炎。 主要特點包括： * **廣效性：** 對多種革蘭氏陽性及陰性病原體有效，包括*巴斯德桿菌*、*鏈球菌*、*葡萄球菌*、*沙門氏菌*和*大腸桿菌*。 * **活性代謝物：** 進入體內後迅速轉化為 desfuroylceftiofur，其抗菌效力與母體藥物相當。 * **臨床要點：** 某些頭孢噻呋製劑（如 Excenel RTU）在泌乳乳牛中具有零天棄乳期的優勢，對酪農業極具價值，但仍需嚴格遵守屠宰停藥期。
作用機制: Ceftiofur is a **time-dependent, bactericidal** antibiotic. * **Mechanism:** It binds to **penicillin-binding proteins (PBPs)** located inside the bacterial cell wall → inhibits the third and final stage of bacterial cell wall synthesis → leads to weakened cell walls, cell lysis, and bacterial death. * **Metabolism Pathway:** Parent ceftiofur is rapidly cleaved into furoic acid and **desfuroylceftiofur** (the primary active metabolite). * **Reservoir Effect:** The active metabolite is highly protein-bound, which creates a 'reservoir effect' that maintains active, therapeutic drug concentrations at the site of infection for extended periods.
各物種劑量
- Susceptible urinary tract infections · 2.2 mg/kg · SC · q24h · Not specified · Authorized for use in dogs in other countries where the main indication is UTI treatment.
- Sepsis/bacteraemia · 4.4 mg/kg · SC · q24h · Not specified · Higher (double) dose indicated to treat sepsis/bacteraemia.
- Bovine respiratory disease and acute bovine interdigital necrobacillosis · 1.1 to 2.2 mg/kg · IM/SC · q24h · 3 days (up to 5 days if needed) · Do not inject more than 15 mL per injection site.
- Bovine respiratory disease (BRD) only · 2.2 mg/kg · IM/SC · q48h · Days 1 and 3 · Do not inject more than 15 mL per injection site.
- Acute post-partum metritis · 2.2 mg/kg · IM/SC · q24h · 5 consecutive days · Do not inject more than 15 mL per injection site.
- Neonatal salmonellosis · 5 mg/kg · IM · q24h · 5 days
- Subclinical mastitis at time of dry off · Infuse one syringe (500 mg) · Intramammary · Once · At dry off · Infuse into each affected quarter.
- Clinical mastitis in lactating dairy cattle · Infuse one syringe (125 mg) · Intramammary · q24h · 2 days (up to 8 consecutive days for extended therapy) · Infuse into each affected quarter.
- Bacterial respiratory disease · 3 to 5 mg/kg · IM · q24h · 3 consecutive days · 1 mL of sterile suspension per 22 to 37 lb body weight.
給藥途徑
禁忌症
- Patients with a documented history of hypersensitivity to cephalosporins
- Use with caution in patients hypersensitive to other beta-lactam antibiotics (e.g., penicillins, carbapenems) due to potential cross-reactivity
不良反應
- Pain on IM injection (especially in small animals)
- Hypersensitivity reactions (rashes, fever, eosinophilia, lymphadenopathy, anaphylaxis)
- Gastrointestinal distress / diarrhea
- Granulocytopenia (rare)
- Thrombocytopenia (rare)
- Injection site discoloration
藥物相互作用
- Aminoglycosides / Nephrotoxic Drugs (e.g., amphotericin B) · Potential for additive nephrotoxicity. In vitro studies show synergistic antibacterial activity, but they must NOT be mixed together in the same syringe or fluid line.
- Probenecid · Competitively blocks the tubular secretion of most cephalosporins, thereby increasing serum levels and prolonging serum half-lives.
- Aminoglycosides · Synergistic antibacterial effect, but should not be mixed in the same syringe due to chemical incompatibility. · moderate
- Amphotericin B · Increased risk of nephrotoxicity. · major
- Loop diuretics (e.g., furosemide) · Increased risk of nephrotoxicity. · major
監測
- Clinical efficacy and resolution of infection
- Weekly CBC monitoring (if used off-label in small animals)
- Renal function parameters in patients with pre-existing renal impairment
- Injection site reactions
過量
Cephalosporin overdoses are generally well-tolerated and unlikely to cause significant problems other than gastrointestinal distress. However, extreme overdoses could theoretically induce hypersensitivity or hematologic abnormalities. > **Important:** Use of dosages in excess of those labeled or via unapproved routes may cause violative tissue or milk residues. Contact FARAD for assistance in determining appropriate withdrawal times if an overdose occurs in food-producing animals.
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。