阿米卡星硫酸鹽
阿米卡星是一種強效的半合成**氨基醣苷類抗生素**，衍生自卡那黴素。主要用於治療嚴重的多重耐藥 (MDR) **革蘭氏陰性需氧菌感染**（如綠膿桿菌、大腸桿菌、克雷伯氏菌、變形桿菌）。由於它能抵抗許多使慶大黴素失活的酶，因此對慶大黴素耐藥菌株通常有效。 **臨床要點：** 氨基醣苷類具有濃度依賴性殺菌活性和顯著的抗生素後效應 (PAE)。因此，現代獸醫學強烈建議**每日一次（高劑量、延長間隔）給藥**，以最大化峰值濃度（提高殺菌效力），同時讓谷值濃度下降，從而降低腎毒性風險。它對真菌、病毒和大多數厭氧菌無效。
作用機制: Amikacin actively transports across the bacterial cell membrane via an **oxygen-dependent mechanism** (which is why it is ineffective against anaerobic bacteria). Once inside, it binds irreversibly to the **30S ribosomal subunit**. Binding to 30S subunit → interferes with the initiation complex between mRNA and the ribosome → causes misreading of the genetic code → produces nonfunctional proteins → leads to rapid bacterial cell death. **Clinical Pearl:** Its antimicrobial activity is significantly enhanced in an alkaline environment and markedly reduced in purulent, acidic, or necrotic debris.
各物種劑量
- Empiric therapy · 10-15 mg/kg · IV/IM/SC · Not specified · Route not specified, assume IV, IM or SC
- Susceptible infections · 15 mg/kg (route not specified) once daily (q24h). Neutropenic or immunocompromised patients may still need to be dosed q8h (dose divided). · Not specified · q24h (or q8h)
- Sepsis · 20 mg/kg once daily IV · IV · q24h
- Susceptible infections · 8-16 mg/kg IM or IV once daily · IM/IV · q24h
- Susceptible infections · 8-16 mg/kg/day SC, IM, IV divided q8-24h · SC/IM/IV · q8-24h
- Susceptible infections · 10 mg/kg IM q8h or 25 mg/kg q12h · IM · q8h or q12h
- Susceptible infections · 22 mg/kg/day IM divided three times daily · IM · TID
- Susceptible infections · 21 mg/kg IV or IM once daily (q24h) · IV/IM · q24h
- Susceptible infections (Neonatal foals) · 21 mg/kg IV once daily · IV · q24h
- Susceptible infections (Neonatal foals) · Initial dose of 25 mg/kg IV once daily · IV · q24h · Strongly recommend to individualize dosage based upon therapeutic drug monitoring.
劑量為合格獸醫專業人員的臨床參考。請務必對照最新藥品仿單及個別病患確認。
給藥途徑
禁忌症
- Hypersensitivity to aminoglycosides
- Generally contraindicated in rabbits/hares (adversely affects GI flora balance)
不良反應
- Nephrotoxicity (tubular necrosis)
- Ototoxicity (auditory and vestibular)
- Neuromuscular blockade
- Facial edema
- Injection site pain/inflammation
- Peripheral neuropathy
- Hypersensitivity reactions
藥物相互作用
- Beta-lactam antibiotics (penicillins, cephalosporins) · May have synergistic effects against some bacteria; potential for physical inactivation of aminoglycosides in vitro (do not mix together) and in vivo (patients in renal failure).
- Cephalosporins · Potentially could cause additive nephrotoxicity (controversial, well documented only with older agents like cephaloridine and cephalothin).
- Loop or Osmotic Diuretics (e.g., furosemide, torsemide, mannitol) · Concurrent use may increase the nephrotoxic or ototoxic potential of the aminoglycosides.
- NSAIDs · May cause nephrotoxic effects; concurrent use with aminoglycosides should generally be avoided.
- Other Nephrotoxic Drugs (e.g., cisplatin, amphotericin B, polymyxin B, vancomycin) · Potential for increased risk for nephrotoxicity.
- Neuromuscular blocking agents & General anesthetics · Concomitant use could potentiate neuromuscular blockade.
監測
- Efficacy (cultures, clinical signs, WBCs)
- Therapeutic drug monitoring (TDM) is highly recommended: Peak level should be at least 40 mcg/mL and the 4-hour trough sample less than 10 mcg/mL
- Renal function tests (BUN, creatinine) and urinalysis (USG, casts) pre-therapy and repeated during therapy
- Gross monitoring of vestibular or auditory toxicity
過量
Should an inadvertent overdosage be administered, three treatments have been recommended: - **Hemodialysis:** Very effective in reducing serum levels but rarely a viable option for veterinary patients. - **Peritoneal dialysis:** Will reduce serum levels but is much less efficacious. - **Complexation:** Complexation of drug with either carbenicillin or ticarcillin (12-20 g/day in humans) is reportedly nearly as effective as hemodialysis.
VetSheet 藥物參考供持牌獸醫專業人員作臨床決策輔助之用,不能取代專業判斷或廠方最新藥品說明書。