Background: Extensively drug resistant (XDR) organisms like Acinetobacter baumannii, pseudomonas aeruginosa XDR, Klebsiella pneumoniae XDR and Carbapenem-resistant Enterobacterales (CRE) leading to pneumonia and blood stream infections (BSI) are associated with high mortality rates and therapeutic modalities became restricted.
Objective: Our clinical trial assessed whether combination therapy with Colistin and meropenem was superior to colistin alone for treatment of the extensively drug resistant Enterobacterals.
Patients and methods: Our study was a randomized, prospective trial, we randomly selected the participants to receive Colistin loading dose of 5 mg/kg once followed by a maintenance dose of 1.67 mg/kg every 8 hours in Combination with either meropenem at a dose of 2 gm every 8 hours or Colistin alone, for treatment of pneumonia and/or Blood stream infection (BSI) caused by extensively resistant (XDR) Acientobacter baumannii, pseudomonas aeruginosa XDR, Klebsiella pneumoniae XDR and Carbapenem resistant Enterobacterals.
Results: Two hundred participants were randomly assigned to treatment by either Colistin as monotherapy or by combination of Colistin and meropenem. Acinetobacter baumannii and Klebsiella pneumoniae were the predominant organisms in our study (67%) and (16%) respectively followed by carbapenem-resistant Enterobacterals (15%) and pneumonia the most common infection (80%). All patients were in the intensive care unit at the time of enrollment (100%). There was a statistical difference in mortality between both groups (79% in colistin group and in combination therapy group was 48%; p < 0.001), clinical improvement (vasopressor requirement, mechanical ventilation settings, inflammatory markers, leucocytic count and radiology) were all in favor of the Combination therapy of Colistin and meropenem.
Conclusion: Colistin and meropenem Combination therapy was more beneficial than monotherapy only for the treatment of pneumonia and/or blood stream infection caused by the XDR Entrobacterals including mortality.