アミカシン
アミカシンは強力なアミノグリコシド系抗生物質であり、主に重篤なグラム陰性菌感染症、黄色ブドウ球菌、およびノカルジア属菌の治療に使用されます。ゲンタマイシンなどの他のアミノグリコシド系に耐性を持つ感染症の治療に特に有用です。 **臨床的警告**: 生体膜の透過性が低いため、全身投与には注射が必要であり、中枢神経系や眼内液への移行は極めて限定的です。**腎毒性**および**耳毒性**の重大なリスクを伴います。
作用機序: Aminoglycosides irreversibly bind to the **30S ribosomal subunit** of susceptible bacteria, inhibiting bacterial protein synthesis. They exhibit **concentration-dependent killing** → leading to a marked **post-antibiotic effect** (PAE). This allows for prolonged dosing intervals (e.g., q24h), which maximizes bacterial kill rates while minimizing accumulation in renal tubular cells, thereby reducing toxicity.
動物種別の用量
- Susceptible bacterial infections · 15-30 mg/kg · IV/IM/SC · q24h · Not specified · IV doses should be given slowly over 30-60 minutes.
- Susceptible bacterial infections in Greyhounds and sight hounds · 12 mg/kg · IV/IM/SC · q24h · Not specified · Lower dose recommended due to a lower volume of distribution in these breeds.
- Sepsis · Higher than standard doses · IV/IM/SC · q24h · Not specified · Recommended by some authors, but carries an increased risk of adverse effects.
- Local infections (e.g., joints, bladder) · Varies · topical · Varies · Not specified · Considered if the site is easily accessible and if the animal shows signs of systemic nephrotoxicity.
- Susceptible bacterial infections · 10-15 mg/kg · IV/IM/SC · q24h · Not specified · IV doses should be given slowly over 30-60 minutes.
- Sepsis · Higher than standard doses · IV/IM/SC · q24h · Not specified · Recommended by some authors, but carries an increased risk of adverse effects.
- Local infections (e.g., joints, bladder) · Varies · topical · Varies · Not specified · Considered if the site is easily accessible and if the animal shows signs of systemic nephrotoxicity.
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
- Animals with pre-existing reduced renal function (unless benefits outweigh risks)
- Dehydrated patients (without concurrent fluid therapy)
有害事象
- Nephrotoxicity (tubular necrosis)
- Ototoxicity (vestibular and auditory dysfunction)
- Neuromuscular blockade (rare but possible)
薬物相互作用
- Beta-lactam antimicrobials (Penicillins, Cephalosporins) · In vivo synergism against susceptible bacteria; however, they can cause in vitro inactivation of amikacin. Do not mix in the same syringe. · moderate
- Amphotericin B · Increased risk of severe nephrotoxicity. · major
- Furosemide · Increased risk of ototoxicity and nephrotoxicity. · major
- Heparin · In vitro inactivation of amikacin. Do not mix in the same syringe. · moderate
- Neuromuscular blocking agents · Potentiation of neuromuscular blockade. · major
モニタリング
- Serum amikacin levels (peak for efficacy, trough for toxicity)
- Renal function (BUN, serum creatinine, urinalysis for casts/proteinuria)
- Hydration status
- Auditory and vestibular function (if possible)
過量投与
Overdosage significantly increases the risk of **acute tubular necrosis (nephrotoxicity)** and **vestibular/auditory damage (ototoxicity)**. Treatment is supportive. Discontinue the drug immediately and initiate aggressive intravenous fluid therapy to promote diuresis and maintain glomerular filtration rate.
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。