頭孢吡肟
頭孢吡肟是一種**第四代頭孢菌素**抗生素，對革蘭氏陽性及革蘭氏陰性病原體均具有廣泛的抗菌活性。 * **結構優勢：** 具有**兩性離子結構**（淨電荷為中性），使其能迅速穿透革蘭氏陰性菌的外膜孔蛋白。 * **β-內醯胺酶穩定性：** 對許多β-內醯胺酶（包括AmpC β-內醯胺酶）具有高度抗水解能力，且不易誘導其產生。 * **抗菌譜：** 對綠膿桿菌（*Pseudomonas aeruginosa*）和腸桿菌科（*Enterobacteriaceae*）具有優異的覆蓋率（類似於頭孢他啶等第三代藥物），同時保留對葡萄球菌和鏈球菌等革蘭氏陽性需氧菌的強大活性。 > **臨床要點：** 由於成本高昂、無口服劑型且需要頻繁給藥（半衰期短），頭孢吡肟通常保留用於重症住院病患（如新生馬駒或敗血症犬隻），特別是在懷疑有多重抗藥性感染，且其他β-內醯胺類、氨基醣苷類或氟喹諾酮類藥物無效或有禁忌症時使用。
作用機制: Cefepime is a **bactericidal**, time-dependent antibiotic that works by disrupting bacterial cell wall synthesis. * **Target Binding:** It rapidly penetrates the bacterial cell envelope and binds with high affinity to specific **penicillin-binding proteins (PBPs)**, primarily PBP 3 and PBP 2. * **Inhibition:** Binding to PBPs inhibits the transpeptidation enzyme responsible for cross-linking peptidoglycan strands. * **Cell Lysis:** The lack of a structurally sound cell wall → activation of bacterial autolysins → **osmotic cell lysis** and bacterial death.
各物種劑量
- For susceptible infections in foals (gram-negative infections) · 11 mg/kg IV q8h · IV · q8h
- Neonates with poor aminoglycoside kinetics or documented multi-resistant infections · 11 mg/kg IV q8h · IV · q8h · Use has been limited primarily to neonates
- For susceptible infections · 40 mg/kg IV q6h · IV · q6h
劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。
給藥途徑
禁忌症
- Hypersensitivity to cefepime or other cephalosporins
- Caution in patients with severe renal impairment (dosage adjustment required)
不良反應
- Loose stools or diarrhea
- Pain on IM injection
- Injection site inflammation
- Hypersensitivity reactions (rash, anaphylaxis)
- Neurologic effects (encephalopathy, seizures) in patients with renal dysfunction
藥物相互作用
- Aminoglycosides · Potential for increased risk of nephrotoxicity; monitor renal function closely.
監測
- Clinical efficacy (resolution of infection signs)
- Renal function (especially in patients with pre-existing renal insufficiency or when used concurrently with nephrotoxic drugs)
過量
No specific information is available for acute toxicity in veterinary patients. In humans with impaired renal function, inadvertent overdoses have led to **encephalopathy, seizures, and neuromuscular excitability**. Treatment should be supportive, and renal function must be monitored.
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。