Meropenem

**Meropenem** is a broad-spectrum, synthetic **carbapenem antibiotic** structurally similar to imipenem. It is highly valued in veterinary medicine as a "big gun" antibiotic for severe, resistant infections. Key characteristics include: * **Broad Spectrum:** Highly effective against many gram-negative bacteria (especially *Enterobacteriaceae*) and anaerobes. It is less active against gram-positive bacteria compared to imipenem. * **Safety Profile:** Unlike imipenem, meropenem does **not** require co-administration with cilastatin and has a significantly lower risk of inducing seizures, making it safer for patients with central nervous system (CNS) disease. * **Administration:** It must be given parenterally (IV or SC). It is advantageous because it can be administered more rapidly and in smaller volumes than imipenem. > **Clinical Pearl:** To practice good antimicrobial stewardship, meropenem should be strictly reserved for documented resistant infections (e.g., multidrug-resistant *E. coli* or *Pseudomonas*) or when first-line options like aminoglycosides are contraindicated due to renal dysfunction.

Mechanism: Meropenem is a bactericidal beta-lactam antibiotic. * It readily penetrates the bacterial cell envelope and binds to specific **penicillin-binding proteins (PBPs)** located inside the bacterial cell wall. * Binding to PBPs → **inhibition of bacterial cell wall synthesis** → weakening of the peptidoglycan network → cell lysis and death. * **Resistance mechanism:** Meropenem is highly resistant to degradation by most beta-lactamases, including penicillinases and cephalosporinases. Furthermore, it is stable against renal **dehydropeptidase-I**, eliminating the need for a protective enzyme inhibitor like cilastatin.

VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.