Clinical outcomes and safety of colistin in treatment of gram negative infections: A prospective observational study

Background

Despite the fact that colistin has a significant activity against MDR gram-negative organisms, its toxicity limits its use. However, the limited therapeutic options due to increasing antibiotic resistance have made re-evaluation of older antibiotics inevitable. In contrast, lack of data to guide the usage of these drugs demands for studies on their safety and efficacy. This studies the clinical outcomes and safety of colistin at a tertiary care centre in Mumbai.

Materials and methods

A prospective observational study was conducted at P.D. Hinduja Hospital, Mumbai for a period of seven months. Diagnosis of infection was based on CDC guidelines and APACHE II score was used to assess the severity of illness. Clinical and microbiological response to colistin was evaluated along with the incidence of nephrotoxicity (RIFLE criteria) and neurotoxicity.

Results

Sixty-two patients (median age 56 years, with documented gram negative bacterial infection and mean APACHE II score 22) received colistin. Clinically favourable response was seen in 71% patients. However, the mortality among the study population was 27%. Univariate analysis identified pneumonia and ICU admission as independent factors for adverse outcome. Deterioration of renal function was observed in 35.89% as per RIFLE criteria. 6 (9.6%) patients demonstrated neurotoxicity.

Conclusion

Colistin is effective in treatment of gram negative infections and its use should be reappraised. However since colistin is the last resort it is imperative to make its best use to ensure that it remains as a safe and effective mode of treatment when need be.