Septic complications after surgery for enterogenous
peritonitis are minimized by adjuvant
antibiotics effective against aerobes and anaerobes. Historically, "gold standard"
therapy included an
aminoglycoside plus
clindamycin, the latter given at 600 mg intravenous piggyback (IVPB), every 6 hours.
Clindamycin pharmacokinetics suggests that it can be given q8h and admixed with
gentamicin, thereby markedly reducing the cost of administration. Although this is now common practice, there is no prospective study comparing the efficacy of the two dose schedules in
peritonitis. This study was designed to test the hypothesis regarding the clinical efficacy of the two regimens. One hundred twenty-six patients with gangrenous (n = 34) or
perforated appendicitis (n = 91) were randomized (2:1) to receive
gentamicin admixed with
clindamycin 900 mg IVPB every 8 hours (Group I n = 80) or
gentamicin IVPB q8h plus
clindamycin 600 mg IVPB every 6 hours (Group II n = 46).
Appendectomy was performed, and aerobic and anaerobic cultures were obtained. Twenty-one patients had simultaneous determinations of
clindamycin levels in plasma, peritoneal fluid, and appendix. Outcome analysis revealed no significant differences in postoperative days of
fever, days non per os,
antibiotic therapy, or hospitalization. There were 6 failures (4
abscesses and 2
wound infections) in Group I and 4 failures (1
abscess and 3
wound infections) in Group II. Both
antibiotic regimens provided clinically equivalent results in
mixed infections due to aerobic and anaerobic bacteria. The admixed
clindamycin, administered every 8 hours, results in at least 20% reduction in costs. This is an important consideration.