セファゾリン
Cefazolin
Cefazolin sodium
別名: Ancef · Kefzol · Zolicef · 46083 · cefazolinum natricum · cephazolin sodium · SKF-41558
VetSheet 獣医チームが監修更新日 2026年4月5日エビデンスに基づく獣医学リファレンス
監査済み v13 用量エビデンス
構造化された用量計算エビデンスSusceptible infections (extra-label)
認証済み獣医師の確認が必要
- q6-8h
NA
必ず考慮する臨床コンテキスト (4)
- 1. If injecting IM, the drug must be injected into a large muscle mass.
- 2. IV injections should be given slowly (ie, over 3 to 5 minutes).
- Cefazolin sodium powder for injection and solutions for injection should be protected from light. The powder for injection should be stored at room temperature (20°C-25°C [68°F-77°F]) but may be exposed to 15°C to 30°C (59°F-86°F) temperatures; temperatures above 40°C (104°F) should be avoided. The frozen solution for injection should be stored at temperatures no higher than -20°C (-4°F).
- After reconstitution, the solution will be stable for 24 hours if kept at room temperature or for 10 days if refrigerated (5°C [41°F]). If, after reconstitution, the solution is immediately frozen in the original container, the preparation will be stable for at least 12 weeks when stored at -20°C (-4°F).
用量は獣医専門家向けの臨床参考資料です。必ず最新の医薬品情報および個別症例に基づいて確認してください。
概要
セファゾリンは、獣医療で広く使用されている注射用の第1世代セファロスポリン系抗生物質です。動物用としてFDAの承認は受けていませんが、外科手術の予防的投与（特に整形外科や軟部組織の手術）や、敗血症を含む全身性感染症の治療において臨床的に極めて重要な薬剤です。
臨床のポイント:
- 抗菌スペクトル: ほとんどのグラム陽性菌（例：Staphylococcus intermedius、黄色ブドウ球菌、レンサ球菌属など）に対して優れた効果を示しますが、グラム陰性菌に対する効果は不安定または不良です。Bacteroides fragilisを除くほとんどの嫌気性菌に対して非常に有効です。
- 薬力学: 時間依存性の殺菌性抗生物質です。有効性は、投与間隔の大部分において、感染部位の薬物濃度を最小発育阻止濃度（MIC）以上に維持できるかどうかに依存します。このパラメータを最適化するため、持続静脈内輸液（CRI）プロトコルがますます利用されています。
- 投与方法: 経口ではほとんど吸収されないため、非経口（IV、IM、SC、IO）で投与する必要があります。副作用を最小限に抑えるため、静脈内注射は3〜5分かけてゆっくりと行う必要があります。
作用機序
Cefazolin is a bactericidal beta-lactam antibiotic.
Mechanism of Action:
- Target: Binds to specific Penicillin-Binding Proteins (PBPs) located inside the bacterial cell wall.
- Pathway: Beta-lactam ring binds PBPs → Inhibition of the transpeptidation enzyme → Prevention of peptidoglycan cross-linking → Weakening of the bacterial cell wall.
- Result: The defective cell wall makes the bacteria highly susceptible to osmotic pressure, leading to cell lysis and death.
As a time-dependent antibiotic, its bacterial killing is maximized by optimizing the duration of time that free drug concentrations remain above the MIC (T > MIC).
安全性・警告
禁忌
- Patients with a known history of hypersensitivity to cephalosporins
有害事象
- Hypersensitivity reactions (rashes, fever, eosinophilia, anaphylaxis)
- Pain at the IM injection site
- Sterile abscesses or local tissue reactions (rare)
- Thrombophlebitis (following IV administration)
- Nephrotoxicity (minimal risk at clinical doses)
- Neurotoxicity or seizures (associated with very high IV doses)
- GI flora disruption (in nursing neonates)
注意事項
Use cautiously in patients with documented hypersensitivity to other beta-lactam antibiotics (e.g., penicillins, carbapenems) due to the potential for cross-reactivity. Dosage adjustments may be necessary in patients with severe renal failure, as the drug is primarily excreted unchanged by the kidneys. Safe use during pregnancy has not been firmly established (FDA Category B), though teratogenic effects have not been documented; use only when benefits outweigh risks. Cefazolin is distributed into milk and may alter neonatal gut flora in nursing dams.
医薬品相互作用
Potential for additive nephrotoxicity; use concurrently with caution.
Potential for additive nephrotoxicity; use concurrently with caution.
Competitively blocks the renal tubular secretion of cefazolin, thereby increasing serum levels and prolonging the elimination half-life.
監視
- Clinical efficacy (resolution of clinical signs, normalization of WBC count, fever reduction)
- Renal function (BUN, creatinine, urinalysis) in patients with pre-existing renal impairment
- Signs of hypersensitivity or injection site reactions
薬物動態
半減期
吸収
Not appreciably absorbed after oral administration; must be given parenterally. In dogs, peak levels occur approximately 30 minutes after IM administration.
分布
Apparent volume of distribution at steady state: 700 mL/kg (dogs), 190 mL/kg (horses), 165 mL/kg (calves). Plasma protein binding is approximately 16-28% in dogs and 4-8% in horses. Crosses the placenta and is distributed into milk.
代謝
Minimal to no hepatic metabolism.
消失
Excreted unchanged by the kidneys into the urine. In dogs, approximately 64% of clearance is attributed to renal tubular secretion. Elimination half-lives may be significantly prolonged in patients with severely diminished renal function.
過剰投与
Cephalosporin overdoses are unlikely to cause significant problems. However, very high doses given rapidly IV could potentially cause seizures or neurotoxicity. Treatment for overdose should be supportive and symptomatic.
製品
製剤
- Powder for injection
- Solution for injection (IV infusion)
ヒト用医薬品
- Cefazolin Sodium Powder for Injection: 500 mg, 1 g, 5 g, 10 g, & 20 g in vials & piggyback vials
- Cefazolin Sodium for Injection (IV infusion): 1 g in 50 mL plastic containers or duplex bags
規制ステータス
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保管・安定性
Protect powder and solutions from light. Store powder at room temperature (15-30°C); avoid temperatures above 40°C. After reconstitution, the solution is stable for 24 hours at room temperature, 96 hours if refrigerated, or at least 12 weeks if immediately frozen at -20°C.
飼主向け情報
セファゾリンは注射用の抗生物質であり、通常は手術中の感染予防や重篤な全身性感染症の治療のために、動物病院で獣医師によって投与されます。
重要なお知らせ: この薬は注射（静脈内または筋肉内）で投与されるため、ご自宅で飲ませる必要はありません。
- アレルギー反応: まれですが、帰宅後にペットにアレルギー反応の兆候（顔の腫れ、じんましん、呼吸困難など）がみられた場合は、すぐに獣医師にご連絡ください。
- 注射部位: 注射部位に軽い痛みを感じることがあります。ひどい腫れ、赤み、痛みに気づいた場合は、獣医師にお知らせください。
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