The penetration of aztreonam, a monobactam antibiotic, into intra-abdominal abscesses

Area of Science:

• Pharmacokinetics
• Infectious Diseases
• Surgical Infections

Background:

• Intra-abdominal abscesses are serious infections.
• Effective antibiotic penetration into abscess cavities is crucial for treatment.
• Aztreonam is a beta-lactam antibiotic with activity against Gram-negative bacteria.

Purpose of the Study:

• To evaluate the penetration of aztreonam into pus.
• To determine aztreonam concentrations in abscess pus over time.
• To compare aztreonam concentrations with minimum inhibitory concentrations (MICs) of relevant pathogens.

Main Methods:

• A low mortality intra-abdominal abscess model was established in Wistar rats.
• Aztreonam serum and pus concentrations were measured at various time points.
• Pharmacokinetic parameters were analyzed.

Main Results:

• Mean peak serum aztreonam concentration was 74.6 mg/l at 30 min.
• Mean pus concentration was 17.04 mg/l at 2 h and 14.47 mg/l at 8 h.
• These pus concentrations were higher than the MICs for most common Gram-negative aerobic bacilli.

Conclusions:

• Aztreonam demonstrates significant penetration into intra-abdominal abscess pus.
• Achieved concentrations in pus are likely to be effective against susceptible Gram-negative pathogens.
• Aztreonam shows promise for treating Gram-negative bacterial infections in intra-abdominal abscesses.