tigecycline + meropenem

Tigecycline + meropenem is a combination of two antibiotics used primarily for the treatment of infections caused by multidrug-resistant Gram-negative bacteria, including carbapenem-resistant Enterobacteriaceae. Tigecycline is a glycylcycline antibiotic structurally related to tetracyclines and acts as a bacteriostatic agent by inhibiting bacterial protein synthesis through reversible binding to the 30S ribosomal subunit, thereby preventing peptide chain elongation[6]. Meropenem is a broad-spectrum carbapenem beta-lactam antibiotic that exerts its bactericidal effect by inhibiting bacterial cell wall synthesis via binding to penicillin-binding proteins. The combination has been explored in clinical settings for severe or resistant infections; however, studies have reported variable outcomes regarding synergy and antagonism between these agents. Some *in vitro* and *in vivo* studies indicate possible antagonistic effects when used together against certain strains (notably KPC-producing *Klebsiella pneumoniae*), suggesting that this combination should be used with caution[1][2][7]. Both drugs are approved individually for use in complicated infections.