Cefepime

Cefepime is a **4th-generation cephalosporin** antibiotic with a broad spectrum of activity against both gram-positive and gram-negative pathogens. * **Structural Advantage:** It possesses a **zwitterionic structure** (having a net neutral charge), which allows it to rapidly penetrate the outer membrane porins of gram-negative bacteria. * **Beta-Lactamase Stability:** It is highly resistant to hydrolysis by many beta-lactamases, including AmpC beta-lactamases, and does not readily induce their production. * **Spectrum:** It offers excellent coverage against *Pseudomonas aeruginosa* and *Enterobacteriaceae* (similar to 3rd-generation agents like ceftazidime) while retaining robust activity against gram-positive aerobes like *Staphylococcus* and *Streptococcus* species. > **Clinical Pearl:** Due to its high cost, lack of oral formulation, and requirement for frequent dosing (short half-life), cefepime is typically reserved for critically ill hospitalized patients (such as neonatal foals or dogs with sepsis) where multi-drug resistant infections are suspected and other beta-lactams, aminoglycosides, or fluoroquinolones are ineffective or contraindicated.

กลไกการออกฤทธิ์: 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.

ข้อมูลอ้างอิงยาของ VetSheet มีไว้สำหรับสัตวแพทย์ผู้มีใบอนุญาตเพื่อช่วยในการตัดสินใจทางคลินิก ไม่ใช่สิ่งทดแทนการวินิจฉัยของผู้เชี่ยวชาญหรือฉลากล่าสุดของผู้ผลิต