ciprofloxacin + metronidazole + neomycin

Ciprofloxacin + metronidazole + neomycin is a combination of three antibiotics, each with distinct mechanisms of action, used to treat mixed infections involving both aerobic and anaerobic bacteria. Ciprofloxacin is a second-generation fluoroquinolone that inhibits bacterial DNA gyrase and topoisomerase IV, leading to the disruption of DNA replication and cell death[2]. Metronidazole is an antimicrobial agent effective against anaerobic bacteria and protozoa; it works by generating free radicals that damage microbial DNA[1][3]. Neomycin is an aminoglycoside antibiotic that binds to the 30S ribosomal subunit, inhibiting protein synthesis in susceptible bacteria[6]. This combination may be considered for complex or mixed infections where broad-spectrum coverage—including both aerobic and anaerobic organisms—is required. While combinations such as ciprofloxacin plus metronidazole or neomycin plus metronidazole are established in clinical practice (e.g., for colorectal surgery prophylaxis), there is limited evidence supporting the routine use of all three agents together.