title: A prospective randomized trial of imipenem-cilastatin versus clindamycin/tobramycin in the treatment of intra-abdominal and pelvic infections.
abstract: OBJECTIVE
  A Canadian multicentre clinical trial in the treatment of intra-abdominal and pelvic infections to compare the efficacy and safety of monotherapy using imipenem-cilastatin (imipenem) (500 mg intravenously every 6 h) versus combination therapy with clindamycin/tobramycin (clindamycin 600 mg intravenously every 6 h and tobramycin 1.7 mg/kg intravenously every 8 h).
  
  
  METHODS
  Two hundred and fifty patients were entered (88 definite and 162 possible infections) and all were evaluable for analysis of adverse events and intention to treat analysis of efficacy. Dichotomous outcomes used were: cured versus noncured (improved, failed, relapsed).
  
  
  RESULTS
  No statistically significant differences were found with the intention to treat analysis (P=0.88) or with definite infections (P=0.81). For overall bacteriological response, no significant differences were noted (P=0.1). Eleven and 15 patients on imipenem and clindamycin/tobramycin, respectively, were colonized with bacteria. Enterococci colonized four of 11 imipenem cases and five of 15 clindamycin/tobramycin cases while fungi colonized six patients on imipenem and four on clindamycin/tobramycin. Five patients on imipenem and seven on clindamycin/tobramycin developed superinfection. In the imipenem group, one case had a bacterial superinfection while four cases were due to Candida albicans. Seven of seven superinfections on clindamycin/tobramycin were bacterial. Three bacteria initially sensitive to the assigned study drug developed resistance. In two patients on imipenem, Enterococcus faecalis and Pseudomonas aeruginosa became resistant after 14 and 10 days of therapy, respectively. On clindamycin/tobramycin, one instance of Bacteroides fragilis resistance after eight days of therapy was seen. Eighty-three adverse events occurred; 47 in the imipenem group and 36 in the clindamycin/tobramycin group. This resulted in discontinuation of antibacterial therapy in 13 patients, seven of whom were on imipenem and six on clindamycin/tobramycin. Comparison of adverse effects showed statistically significant differences for nausea (P=0.02) and hepatotoxicity (P=0.05) occurring with greater frequency in the imipenem and clindamycin/tobramycin groups, respectively.
  
  
  CONCLUSIONS
  These data support the conclusion that monotherapy with imipenem (500 mg intravenously every 6 h) is as efficacious as clindamycin/tobramycin for treatment of intra-abdominal and pelvic infections. Both regimens are well tolerated.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Henderson General Hospital and McMaster University, Hamilton, Ontario; Service of Microbiology and Infectious Diseases, Hôpital Saint-Luc and l'Université de Montréal, Montréal, Québec; and Department of Medicine and Medical Microbiology, The University of Manitoba, Winnipeg, Manitoba.
authors.forename: L A
authors.initials: LA
authors.lastname: Mandell
authors.forename: P L
authors.initials: PL
authors.lastname: Turgeon
authors.forename: A R
authors.initials: AR
authors.lastname: Ronalds