ceftazidime + gentamicin

Ceftazidime + gentamicin is a combination of two injectable antibiotics used primarily for the treatment of severe infections caused by susceptible Gram-negative bacteria, including Pseudomonas aeruginosa. Ceftazidime is a third-generation cephalosporin (beta-lactam) antibiotic that exerts its bactericidal effect by inhibiting bacterial cell wall synthesis through binding to penicillin-binding protein 3 (PBP3), leading to cell lysis. Gentamicin is an aminoglycoside antibiotic that binds irreversibly to the 30S subunit of bacterial ribosomes, inhibiting protein synthesis and causing misreading of mRNA, which results in bacterial death. The combination may be used synergistically in severe or resistant infections but carries an increased risk of nephrotoxicity and ototoxicity; careful monitoring is required[2][4][6]. This regimen is often reserved for life-threatening or hospital-acquired infections where multidrug-resistant organisms are suspected.