Ertapenem versus piperacillin/tazobactam for diabetic foot infections (SIDESTEP): prospective, randomised, controlled, double-blinded, multicentre trial.
BACKGROUND
Diabetic foot infections are a common and serious problem, yet few randomised trials of adequate quality have compared the efficacy of the various antibiotic regimens available for their treatment. Our aim was to assess the efficacy and safety of ertapenem versus piperacillin/tazobactam for foot infections.


METHODS
We did a randomised, double-blinded, multicentre trial in adults (n=586) with diabetes and a foot infection classified as moderate-to-severe and requiring intravenous antibiotics. We assigned patients intravenous ertapenem (1 g daily; n=295) or piperacillin/tazobactam (3.375 g every 6 h; n=291) given for a minimum of 5 days, after which oral amoxicillin/clavulanic acid (875/125 mg every 12 h) could be given for up to 23 days. Investigators retained the option to administer vancomycin to patients in either group to ensure adequate coverage for potentially antibiotic resistant Enterococcus spp and meticillin-resistant Staphylococcus aureus (MRSA). Our primary outcome was the proportion of patients with a favourable clinical response (cure or improvement) on the day that intravenous antibiotic was discontinued. Analyses were by an evaluable-patient only approach. This study is registered with , number NCT00229112.


RESULTS
Of the 576 patients treated, 445 were available for assessment at the end of intravenous therapy. Both baseline characteristics and favourable clinical response rates were similar for the 226 who received ertapenem and the 219 who received piperacillin/tazobactam (94%vs 92%, respectively; between treatment difference 1.9%, 95% CI -2.9 to 6.9). Rates of favourable microbiological responses (eradication rates and clinical outcomes, by pathogen) and adverse events did not differ between groups.


CONCLUSIONS
Clinical and microbiological outcomes for patients treated with ertapenem were equivalent to those for patients treated with piperacillin/tazobactam, suggesting that this once-daily antibiotic should be considered for parenteral therapy of diabetic foot infections, when deemed appropriate.
Lipsky
Benjamin A
BA
University of Washington School of Medicine and Veterans' Affairs Puget Sound Health Care System (S-111-GIMC), 1660 S Columbian Way, Seattle, WA 98108, USA. Benjamin.Lipsky@med.va.gov
Armstrong
David G
DG
Citron
Diane M
DM
Tice
Alan D
AD
Morgenstern
David E
DE
Abramson
Murray A
MA
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D017719:Diabetic Foot / Q000145:classification / Q000188:drug therapy* / Q000382:microbiology; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D000077727:Ertapenem; D005260:Female; D006090:Gram-Negative Bacteria / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000627:therapeutic use; D010878:Piperacillin / Q000627:therapeutic use; D000077725:Piperacillin, Tazobactam Drug Combination; D012720:Severity of Illness Index; D016896:Treatment Outcome; D047090:beta-Lactams / Q000627:therapeutic use*
D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D000077725:Piperacillin, Tazobactam Drug Combination; D010397:Penicillanic Acid; D000077727:Ertapenem; D010878:Piperacillin