Colistin Use in Combination with Other Antibiotics for the Treatment of Multiple Drug Resistant Gram-negative Bacterial Infections

Abstract

Objective: To describe the effectiveness and safety of colistin use in combination with other antibiotics in multiple drug resistant gram negative bacterial infections. Methods: The descriptive cohort study was performed in patients above 18 years old who received colistin with other antibiotics and whose microbiology test found multiple drug resistant gram negative bacteria during hospitalization in medical wards at Mahasarakham hospital. The researchers assessed all-cause mortality, duration of hospitalization, and drug safety or adverse drug reaction (ADR). Results: There were 69 eligible patients, 43 were male (62.3%), mean age 60.16+17.02 years. Fifty-one patients had comorbidities (73.9%), most were diabetes mellitus (37.2%). Severity of illness assessed by using the APACHE II average score was 12.00±5.49 and 62 patients received ventilator therapy (89.9%). Pneumonia was the major problem of these patients (66.7%). Patients were infected by one of three multiple drug resistant bacteria; Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella pneumoniae (65.2%, 20.3% and 7.2% respectively). Mortality rate was 33.3% (23 patients). Duration of hospitalization was 37.52+45.48 days. Most of drugs used in combination with colistin were meropenem and cefoperazone/sulbactam (58.0% and 21.7% respectively), and the mortality rate of patients using these two drugs were 35.0% and 33.3% respectively. There were no statistically significant differences regarding mortality among patients receiving different antimicrobials (P=0.526). Adverse drug reactions were found in 14 patients (20.3%); nephropathy in 13 patients and drug allergy in 1 patient. There were no statistically significant differences in rate of ADR among patients receiving different combined antibiotics (P=0.064). Conclusion: The most prevalent drugs used in combination with colistin were meropenem and cefoperazone/sulbatam. All-cause mortality and ADR rate were not different among patients with different combined antibiotics. The most frequent ADR was nephrotoxicity consistent with that found in most studies.