セフチオフルナトリウム
セフチオフルナトリウムは、**獣医専用の第3世代セファロスポリン系**抗生物質です。グラム陽性菌およびグラム陰性菌の両方に対して広域スペクトルな有効性を持ち、複数の動物種で広く利用されています。 **主な臨床的特徴：** * **主な適応症：** 牛および豚の呼吸器疾患、牛の趾間腐爛（フットロット）、ならびに犬および猫の感受性尿路感染症（UTI）や軟部組織感染症に非常に有効です。 * **適応外使用：** エキゾチックアニマル（爬虫類、走鳥類、ゾウなど）や、小動物の様々な全身性感染症に対して適応外で頻繁に使用されます。 * **安全性プロファイル：** 概ね安全ですが、筋肉内（IM）注射時に一過性の痛みを引き起こすことがあります。過敏反応のリスクがあり、既知のβ-ラクタム系アレルギーを持つ患者には注意が必要です。 * **代謝：** 生体内で速やかに活性代謝物であるデスフロイルセフチオフルに変換され、強力な抗菌活性を維持します。
作用機序: 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.
動物種別の用量
- 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
投与経路
禁忌
- Patients with a history of hypersensitivity to cephalosporins
- Caution in patients with documented hypersensitivity to other beta-lactam antibiotics (penicillins, cefamycins, carbapenems)
有害事象
- 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
薬物相互作用
- 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.
モニタリング
- Clinical efficacy (resolution of infection signs)
- Weekly CBC in small animals (recommended by some clinicians)
- Intensified renal monitoring in patients with diminished renal function
過量投与
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 の薬剤リファレンスは、獣医療従事者向けの臨床意思決定支援を目的としており、専門的判断やメーカーの最新添付文書に代わるものではありません。