イミペネム・シラスタチンナトリウム
Imipenem-Cilastatin Sodium
Imipenem monohydrate / Cilastatin sodium
別名: Primaxin · Klonam · Tenacid · Tienam · Tracix · Zienam · N-formimidoyl thienamycin · imipemide · MK-787 · MK-0787
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
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。
動物種別用量
🌎 NA — North America🌍 EU — Europe
犬
| 適応 | 用量 | 経路 | 頻度 | 期間 | 地域 |
|---|---|---|---|---|---|
| Susceptible infections | 5-10 mg/kg | IV, SC or IM | q8h | — | 🌎 NA |
| Susceptible infections | 5-10 mg/kg | IV or IM | q6h | — | 🌎 NA |
| Tissue infections | 3-7.5 mg/kg | IV, SC or IM | q4-6h | 3-5 days | 🌎 NA |
| Sepsis, more resistant organisms | 5 mg/kg | IV | q4h | 3-5 days | 🌎 NA |
| Treatment of Nocardiosis | 2-5 mg/kg | IV | q8h | — | 🌎 NA |
- Susceptible infections: IM form is different
- Susceptible infections: IV given over 30 minutes. IM mixed with 1% lidocaine to reduce pain. Cannot interchange IV and IM dosage forms.
- Sepsis, more resistant organisms: Multi-drug resistant bacteria may require q2h dosing
猫
| 適応 | 用量 | 経路 | 頻度 | 期間 | 地域 |
|---|---|---|---|---|---|
| Susceptible infections | 5-10 mg/kg | IV, SC or IM | q8h | — | 🌎 NA |
| Susceptible infections | 5-10 mg/kg | IV or IM | q6h | — | 🌎 NA |
| Tissue infections | 3-7.5 mg/kg | IV, SC or IM | q4-6h | 3-5 days | 🌎 NA |
| Sepsis, more resistant organisms | 5 mg/kg | IV | q4h | 3-5 days | 🌎 NA |
| Treatment of Nocardiosis | 2-5 mg/kg | IV | q8h | — | 🌎 NA |
- Susceptible infections: IM form is different
- Susceptible infections: IV given over 30 minutes. IM mixed with 1% lidocaine to reduce pain. Cannot interchange IV and IM dosage forms.
- Sepsis, more resistant organisms: Multi-drug resistant bacteria may require q2h dosing
馬
| 適応 | 用量 | 経路 | 頻度 | 期間 | 地域 |
|---|---|---|---|---|---|
| Susceptible infections (Adult horses) | 10-20 mg/kg | IV | q6h | — | 🌎 NA |
| Susceptible infections (Foals) | 10-20 mg/kg | IV | q6h | — | 🌎 NA |
| Susceptible infections (Foals) | 10-15 mg/kg | IV or IM | q6-12h | — | 🌎 NA |
- Susceptible infections (Adult horses): Give via slow IV over a 10 minute period. Alternatively, a CRI of 16 micrograms/kg/minute should maintain synovial concentrations > 1 microgram/mL.
- Susceptible infections (Foals): IM if diluted into 1% lidocaine. May give as a CRI at 0.4-0.8 mg/kg/hr.
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
イミペネム・シラスタチンは、獣医学において重篤で生命を脅かす感染症や多剤耐性菌感染症のために予約されている、強力で広域スペクトルを持つ静脈内/筋肉内投与用の抗菌薬配合剤です。
- イミペネムは、グラム陽性菌、グラム陰性菌、および嫌気性菌を含む非常に広い抗菌スペクトルを持つカルバペネム系抗菌薬です。緑膿菌や腸内細菌科（ESBL産生菌など）のような耐性グラム陰性菌に対して特に有用です。
- シラスタチンはデヒドロペプチダーゼI（DHP I）阻害薬です。それ自体に抗菌活性はありませんが、腎臓の酵素によるイミペネムの急速な分解を防ぐため、非常に重要です。
臨床のポイント: その広いスペクトルと高度耐性感染症治療における重要性から、イミペネムは「切り札」または予備の抗菌薬と見なされています。カルバペネム耐性菌の出現を防ぐため、理想的には培養および感受性試験に基づいて使用されるべきです。
作用機序
The drug functions through a synergistic two-part mechanism:
- Imipenem (Bactericidal Action): Imipenem penetrates bacterial cell envelopes and binds with high affinity to penicillin-binding proteins (PBPs) (specifically PBP-2 and PBP-1B in gram-negative bacteria) → inhibits peptidoglycan cross-linking → disrupts bacterial cell wall synthesis → leads to cell lysis and death.
- Cilastatin (Pharmacokinetic Enhancer): Imipenem is normally rapidly metabolized by dehydropeptidase I (DHP I), an enzyme located on the brush borders of the proximal renal tubules. Cilastatin competitively inhibits DHP I → prevents imipenem degradation → ensures high, therapeutic antibacterial concentrations in the urine and protects the patient from proximal renal tubular necrosis that can occur if imipenem is administered alone.
安全性・警告
禁忌
- Patients with known hypersensitivity to imipenem, cilastatin, or other beta-lactam antibiotics (due to partial cross-reactivity)
- Caution in patients with renal impairment (dosage adjustment required)
- Caution in patients with underlying CNS disorders (e.g., seizures, head trauma) due to increased risk of neurotoxicity
有害事象
- Gastrointestinal upset (vomiting, anorexia, diarrhea)
- CNS toxicity (seizures, tremors)
- Hypersensitivity reactions (pruritus, fever, anaphylaxis)
- Infusion reactions (thrombophlebitis)
- Severe pain and potential neurovascular damage at IM injection sites
- Transient increases in BUN, serum creatinine, AST, ALT, and Alkaline Phosphatase
- Hypotension or tachycardia (rare)
注意事項
CRITICAL WARNINGS:
- Do NOT administer via rapid IV infusion. Rapid infusion significantly increases the risk of CNS toxicity and seizures. Doses ≤ 500 mg should be given over 20-30 minutes; doses > 500 mg should be given over 40-60 minutes.
- Formulation Specificity: The IV and IM dosage forms are NOT interchangeable. If giving IM or SC, the specific IM product must be used.
- Renal Impairment: Animals with reduced renal function (including neonates and geriatrics) are at a higher risk for seizures. Dosages may need to be reduced or dosing intervals extended.
- IM Administration: Can cause severe pain. It is recommended to dilute the IM form in 1% lidocaine (without epinephrine) to relieve associated pain.
医薬品相互作用
Additive effects or synergy may result, particularly against Enterococcus, Staph. aureus, and Listeria monocytogenes. No synergy or antagonism noted against Enterobacteriaceae or Pseudomonas aeruginosa.
Antagonism may occur against several Enterobacteriaceae (including Pseudomonas aeruginosa, Klebsiella, Enterobacter, Serratia). Concurrent use is not recommended.
May antagonize the antibacterial effects of imipenem (based on in vitro evidence).
May increase concentrations and elimination half-life of cilastatin, but not imipenem; concurrent use is not recommended.
Synergy may occur against Nocardia asteroides when used in combination.
監視
- Clinical efficacy (resolution of infection signs)
- Adverse effects (especially CNS signs like tremors or seizures)
- Renal and hepatic function tests (BUN, creatinine, AST, ALT, Alk Phos) if treatment is prolonged or if the patient has pre-existing organ dysfunction
薬物動態
半減期
吸収
Not absorbed appreciably from the GI tract. Bioavailability after IM injection is ~95% for imipenem and 75% for cilastatin. In dogs, SC bioavailability of imipenem is complete.
分布
Distributed widely throughout the body, with the exception of the CSF. Crosses the placenta and is distributed into milk.
代謝
Imipenem is metabolized by dehydropeptidase I (DHP 1) in the kidneys; this metabolism is inhibited by the concurrent administration of cilastatin.
消失
Eliminated by both renal and non-renal mechanisms. Approximately 75% of a dose is excreted in the urine and about 25% by unknown non-renal mechanisms.
過剰投与
Information on acute toxicity is limited. The LD50 of imipenem:cilastatin (1:1 ratio) in mice and rats is approximately 1 gram/kg/day.
Management:
- Halt therapy immediately.
- Provide supportive and symptomatic care (e.g., anticonvulsants if seizures occur, fluid therapy to support renal clearance).
製品
製剤
- Powder for Injection (IV)
- Powder for Injection (IM)
ヒト用医薬品
- Imipenem Cilastatin Powder for Injection: 250 mg imipenem / 250 mg cilastatin (Primaxin I.V.)
- Imipenem Cilastatin Powder for Injection: 500 mg imipenem / 500 mg cilastatin (Primaxin I.V.)
- Imipenem Cilastatin Powder for Injection: 500 mg imipenem / 500 mg cilastatin (Primaxin I.M.)
規制ステータス
規制データなし: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
保管・安定性
Store commercially available sterile powders at room temperature (<25°C). After reconstitution, IV solutions are stable for 4 hours at room temperature or 10 hours when refrigerated. Do not freeze. The IM suspension (reconstituted with 1% lidocaine) must be used within one hour.
飼主向け情報
イミペネム・シラスタチンについて知っておくべきこと:
- 入院環境: これは、重度または高度な耐性を持つ感染症のために通常予約されている、非常に専門的で強力な抗菌薬です。ペットを注意深く監視できるよう、ほぼ例外なく動物病院内で投与されます。
- 投与方法: 注射（通常は静脈カテーテルまたは筋肉内）で投与する必要があります。筋肉内に投与する場合、痛みを伴うことがあるため、獣医師はペットの不快感を和らげるために局所麻酔薬と混ぜることがあります。
- 副作用: 監視下では一般的に安全ですが、胃腸の不調（嘔吐、食欲不振、下痢）を引き起こす可能性があります。まれに、震えや発作などの神経症状を引き起こすことがあります。ペットの面会中に痙攣や異常な動きに気づいた場合は、すぐに獣医療スタッフに知らせてください。
- 費用: これは高度な人間用病院レベルの抗菌薬であるため、治療費がかなり高額になる可能性があります。獣医師が費用の見積もりについてご説明します。
VetSheet医薬品リファレンスは獣医専門家の臨床意思決定支援を目的としており、専門的判断または製造業者の最新医薬品情報の代替にはなりません。