Combined aminoglycoside + β-lactam therapy

Combined aminoglycoside and β-lactam therapy is a synergistic pharmacological strategy used primarily to treat severe bacterial infections, including those caused by Gram-negative pathogens like Pseudomonas aeruginosa and Gram-positive organisms like Enterococcus species (StatPearls, 2023). The β-lactam component disrupts the bacterial cell wall by inhibiting penicillin-binding proteins, which enhances the uptake of the aminoglycoside into the bacterial cytoplasm (Davis, 1982). Once inside, the aminoglycoside binds to the 30S ribosomal subunit, leading to mistranslation and inhibition of protein synthesis (StatPearls, 2023). This combination is often employed in clinical settings such as febrile neutropenia, endocarditis, and sepsis to broaden the antimicrobial spectrum and achieve rapid bactericidal activity (Moellering et al., 1986). However, the use of this regimen requires careful monitoring due to the risk of aminoglycoside-induced nephrotoxicity and ototoxicity, and recent meta-analyses have questioned its routine superiority over β-lactam monotherapy in certain conditions (Cochrane, 2014).

Other names

Aminoglycoside and beta-lactam combinationSynergistic antibiotic therapyBeta-lactam-aminoglycoside synergyBLAG combination

The combination exhibits synergy where β-lactams disrupt bacterial cell wall integrity by inhibiting penicillin-binding proteins (PBPs), which enhances the intracellular uptake of aminoglycosides; the aminoglycosides then bind to the 30S ribosomal subunit to irreversibly inhibit protein synthesis (Davis, 1982; Moellering et al., 1986).