頭孢噻呋鈉
頭孢噻呋鈉是一種**獸醫專用的第三代頭孢菌素類**抗生素。它對多種革蘭氏陽性及革蘭氏陰性細菌具有廣效的抗菌作用，廣泛應用於多種動物。 **主要臨床重點：** * **主要適應症：** 對牛和豬的呼吸道疾病、牛的腐蹄病，以及犬貓的敏感性泌尿道感染 (UTIs) 和軟組織感染非常有效。 * **標示外使用：** 經常在標示外用於特寵（包括爬蟲類、平胸鳥類和大象）以及小動物的各種全身性感染。 * **安全性：** 通常安全，但肌肉注射 (IM) 時可能會引起短暫疼痛。具有引發過敏反應的風險，已知對β-內醯胺類過敏的病患應謹慎使用。 * **代謝：** 在體內迅速轉化為其活性代謝物 desfuroylceftiofur，並保持強效的抗菌活性。
作用機制: Ceftiofur is a **time-dependent, bactericidal** antibiotic. Upon administration, ceftiofur is rapidly cleaved → **furoic acid** and **desfuroylceftiofur** (the primary active metabolite). Desfuroylceftiofur → binds to **penicillin-binding proteins (PBPs)** located inside the bacterial cell wall → inhibits the third and final stage of bacterial cell wall synthesis by halting peptidoglycan cross-linking → weakens the structural integrity of the cell wall → leads to **cell lysis** and bacterial death.
各物種劑量
- Respiratory disease · 1.1 to 2.2 mg/kg · IM · q24h · 3-5 days · 1-2 mL reconstituted sterile solution per 100 lbs body weight
- Respiratory disease · 1.1 to 2.2 mg/kg · IM · q24h · 3-5 days · When used in lactating does, the high end of the dosage is recommended
- UTI · 2.2 mg/kg · SC · q24h · 5-14 days
- Systemic, soft tissue infections · 2.2 mg/kg q12h or 4.4 mg/kg q24h · SC · q12h or q24h · 5-14 days
- Sepsis, bacteremia · 4.4 mg/kg · SC · q12h · 2-5 days
- Bovine respiratory disease, foot rot · 1.1 to 2.2 mg/kg · IM or SC · q24h · 3-5 days · 1-2 mL reconstituted sterile solution per 100 lbs body weight
- Respiratory infections (S. zooepidemicus) · 2.2 to 4.4 mg/kg · IM · q24h · up to 10 days · Continue for 48 hours after symptoms disappear. Max 10 mL per injection site.
- General susceptible infections · 1-2 mg/kg · IV or IM · q12-24h
給藥途徑
禁忌症
- Patients with a history of hypersensitivity to cephalosporins
- Caution in patients with documented hypersensitivity to other beta-lactam antibiotics (penicillins, cefamycins, carbapenems)
不良反應
- Immediate and transient local pain on IM injection
- Discoloration at SC injection sites (may persist >5 days)
- Localized post-injection bacterial infections/abscesses (cattle)
- Hypersensitivity reactions (rashes, fever, eosinophilia, lymphadenopathy, anaphylaxis)
- Acute diarrhea (especially in stressed horses)
- Granulocytopenia
- Thrombocytopenia
藥物相互作用
- Aminoglycosides · Potential for additive nephrotoxicity; in vitro synergy exists, but drugs should not be mixed in the same syringe/fluid line.
- Nephrotoxic drugs (e.g., Amphotericin B) · Potential for additive nephrotoxicity.
- Probenecid · Competitively blocks the tubular secretion of most cephalosporins, increasing serum levels and serum half-lives.
監測
- Clinical efficacy (resolution of infection signs)
- Weekly CBC in small animals (recommended by some clinicians)
- Intensified renal monitoring in patients with diminished renal function
過量
Cephalosporin overdoses are generally well-tolerated and unlikely to cause significant systemic toxicity. * **Clinical Signs:** Primarily limited to gastrointestinal distress (nausea, vomiting, diarrhea) or localized injection site reactions. * **Food Animal Considerations:** Overdoses in food-producing animals may result in significantly extended tissue withdrawal times. Contact FARAD for specific guidance on withdrawal interval adjustments.
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。