ピペラシリンナトリウム・タゾバクタムナトリウム
**ピペラシリン/タゾバクタム**は、β-ラクタマーゼ阻害剤を配合した強力な広域スペクトル抗緑膿菌ペニシリンです。 * **広域スペクトル**: 緑膿菌を含む多くのグラム陽性菌、グラム陰性菌、嫌気性菌に対して拡張された抗菌スペクトルを提供します。 * **臨床用途**: 重篤で生命を脅かす感染症、培養結果が出るまでの経験的治療、または混合感染が懸念される外科的予防にしばしば予約されます。 * **獣医療での背景**: 獣医療での経験は限られていますが、腹腔内敗血症や重度の菌血症に対して非常に安全で効果的であると考えられています。
作用機序: * **Piperacillin** is a bactericidal beta-lactam antibiotic. It binds to specific **penicillin-binding proteins (PBPs)** located inside the bacterial cell wall → inhibits the third and last stage of bacterial cell wall synthesis → cell lysis and death. * **Tazobactam** is a "suicide" inhibitor. It irreversibly binds to **beta-lactamases** (Richmond-Sykes types II-V) → prevents these enzymes from hydrolyzing the beta-lactam ring of piperacillin. * **Synergy**: Tazobactam itself has minimal antibacterial activity, but its combination with piperacillin restores and expands piperacillin's efficacy against beta-lactamase-producing organisms.
動物種別の用量
- Single-agent therapy of intra-abdominal sepsis · 50 mg/kg · IV or IM · q4-6h · 5-7 days · Dose extrapolated from human dosage with limited studies in dogs or cats.
- Susceptible infections · 100 mg/kg · IM · q8-12h · Reconstitute to 200 mg/mL.
- Severe polymicrobic bacteremia · 100 mg/kg · IV · q6h
- Preoperative orthopedic or coelomic surgery · 100 mg/kg · IM · q12h
- Single-agent therapy of intra-abdominal sepsis · 50 mg/kg · IV or IM · q4-6h · 5-7 days · Dose extrapolated from human dosage with limited studies in dogs or cats.
- Bacterial sepsis · 3.375 grams (total dose per dog) IV q6h or 4.5 grams (total dose per dog) IV q8h · IV · q6h or q8h · 7 days · Total dose per dog.
- Life-threatening infections (e.g., Pseudomonas) · 80-100 mg/kg · IV · q8h · Human paediatric dose used as a guide; administer by slow IV injection/infusion.
- Life-threatening infections · 25-50 mg/kg · IV · q4-6h · Empirical dosing.
用量は獣医療従事者向けの臨床リファレンスです。必ず最新の添付文書と個々の患者で確認してください。
投与経路
禁忌
- Patients with documented hypersensitive reactions to a beta-lactam or beta-lactamase inhibitor
- Known hypersensitivity to penicillins or cephalosporins
有害事象
- Hypersensitivity reactions
- Local effects (thrombophlebitis) associated with IV injection
- Antibiotic-associated diarrhea (alterations in gut flora)
- Coagulation abnormalities (rare, particularly in renal failure)
- Neurotoxicity/seizures (at very high doses, especially with diminished renal function)
- Clostridium difficile superinfections (rare)
- Nausea
- Diarrhoea
- Skin rashes
- Pain on intramuscular injection
- Sodium overload (in susceptible patients)
薬物相互作用
- Aminoglycosides (amikacin, gentamicin, tobramycin) · Synergistic or additive activity against certain bacteria. However, penicillins can inactivate aminoglycosides in vitro and in vivo in patients in renal failure or at massive dosages. Amikacin is the most resistant to this inactivation.
- Anticoagulants (heparin, warfarin) · Piperacillin may rarely affect platelets; increased monitoring of coagulation parameters is suggested.
- Methotrexate · Piperacillin may increase MTX serum levels.
- Probenecid · Can reduce the renal tubular secretion of both piperacillin and tazobactam, maintaining higher systemic levels for a longer period.
- Vecuronium · Piperacillin may prolong neuromuscular blockade.
- Non-depolarizing muscle relaxants · Piperacillin enhances the effects of non-depolarizing muscle relaxants. · moderate
- Gentamicin · Inactivates piperacillin if mixed in the same syringe. · major
- Aminoglycosides · Synergistic bactericidal effect against pseudomonal septicaemias when administered systemically (not mixed in vitro). · minor
モニタリング
- Efficacy for the infection treated (CBC, clinical signs, etc.)
- Coagulation parameters (if patient is concurrently on anticoagulants)
- Clinical efficacy
- Culture and sensitivity results
- Renal function
- Electrolytes (specifically sodium) in patients with cardiac or renal impairment
過量投与
Single overdoses are unlikely to pose much risk, although very large overdoses may cause vomiting, diarrhea, or neurotoxicity. * **Toxicity Studies:** Dogs receiving up to 800 mg/kg/day of piperacillin/tazobactam for 6 months demonstrated no serious toxic effects. Doses at 400 mg/kg/day or greater caused some transient effects to the liver (glycogen granules in the cytoplasm and increases in smooth endoplasmic reticulum in hepatocytes) that were mostly reversed after one month. * **Treatment:** Treatment for overdoses, if required, is supportive.
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。