Abstract

Secondary bacterial peritonitis is usually a polymicrobial infection of facultative gram-negative aerobic and anaerobic organisms. Treatment consists of operation and broad-spectrum antibiotic administration. The antibiotic treatment of choice in these infections has been the combination of gentamicin and clindamycin. However, this combination can have toxic side effects and necessitates frequent monitoring of serum levels. Beta-lactam antibiotics provide broad-spectrum coverage and low toxicity, but can be inactivated by species of bacteria producing beta-lactamase enzymes. Clavulanic acid is a potent inhibitor of beta-lactamases and has been shown to extend the efficacy of ticarcillin to bacteria producing these enzymes. This combination was compared with gentamicin and clindamycin in 99 consecutive patients with complicated appendicitis. Eradication of identified pathogens was greater in the ticarcillin and clavulanate group (98 per cent) than in the gentamicin and clindamycin group (92 per cent), even for the subgroup of organisms producing beta-lactamases (97 versus 90 per cent eradication). Complications and clinical response were not significantly different between the two treatment groups. Ticarcillin and clavulanic acid is a safe and effective alternative to gentamicin and clindamycin in the treatment of secondary bacterial peritonitis and offers advantages in dosing simplicity and freedom from ototoxic and nephrotoxic effects.