Reinforcement of an antimicrobial stewardship task force aims at a better use of antibiotics of last resort: the COLITIFOS study

- Last-resort drugs are mainly prescribed for gram-negative bacteria (69.2%).
- The percentage of patients treated for an MDR or XDR organism are 59.7% and 10.4% respectively.
- Antimicrobial stewardship aims at better use of last-resort antibiotics.
- By a reduction in prescriptions for susceptible microorganisms (from 29.2% to 6.9%).
- By avoiding inappropriate doses (from 56.2% to 27.6%) (P = 0.02).

BackgroundPhysicians are facing a worldwide increase in multidrug-resistant (MDR) organisms. Eradication of such bacteria, including so called superbugs (XDR), may cause physicians to prescribe last-resort antibiotics. However, experience with these drugs is limited and few data are available.MethodsA before and after retrospective study was conducted from January 2008 to June 2016. Prescriptions of parenteral antimicrobials considered as last-resort antibiotics (colistin, fosfomycin, tigecycline and temocillin) were reviewed by 4 infectious disease specialists (according to microbiology results, susceptibility testing, clinical situation and alternative agents), while doses were analysed by a pharmacist. As a second step, the cohort was split before and after 2013 coinciding with the arrival of a referent in antimicrobial stewardship.ResultsThe treatment of 77 patients with a mean age of 55.4 ± 18.7 years was analysed. The majority were treated for gram-negative rods (69.2%), especially Pseudomonas and Klebsiella spp. and Escherichia coli while 20.0% of patients were treated for gram-positive cocci (mainly Staphylococcus aureus) and the remainder were polymicrobial. Of 84 prescriptions, fosfomycin was the most frequently prescribed (47.6%), followed by colistin (40.5%), tigecycline (10.7%) and temocillin (1.2%). Outcomes were favorable in 75.3% of patients. In patients with MDR and XDR infections (n = 54), the mortality rate was 11.1%. After 2013, there were significantly fewer prescriptions of last-resort antibiotics for susceptible microorganisms (29.2% vs 6.9%), in the absence of supporting microbiology results (22.9% vs 3.5%) and fewer dose errors (56.2% vs 27.6%) (P = 0.02).ConclusionReinforcement of the antimicrobial stewardship task force seems to be valuable for promoting the better use of last-resort antibiotics.