Efficacy of local application of colistimethate sodium in non-healing wounds infected by multidrug resistant bacteria

Efficacy of local application of colistimethate sodium in non-healing wounds infected by multidrug resistant bacteria

Sanju Samuel
Amrita Institute of Medical Sciences and Research Centre, Kochi, India

Introduction: Multi drug resistant(MDR) bacteria infecting wounds have become important in recent years due to increased prevalence and their possible deleterious consequences. Such wounds have been treated successfully using surgical debridement or by parenteral antibiotics based on Culture and sensitivity(C/S). Oral or parenteral antibiotic therapy then becomes the cornerstone of treating such conditions. However, treatment of multi drug resistant bacteria that are sensitive only to reserve antibiotics is a cause of concern. These antibiotics are expensive and have a higher risk of renal, liver and multisystem compromise.

Methodology: We present a case series of five patients with non-healing wounds infected by MDR bacteria treated with local application of colistimethate sodium(CMS).All the five patients had sepsis, deranged renal functions and grew MDR gram negative bacteria(Kliebsiella/Pseudomonas) sensitive to colistin only. Two patients also had a compromised liver. Wound size was measured and C/S was done at start of treatment and at three weeks to assess response. After an initial surgical debridement, one vial of CMS powder was mixed with a tube of ointment containing papain 521700IU+urea 100mg and the mixture was applied locally on the wound twice a day for 1week till healthy granulation tissue appeared or negative culture report. There was a good response and healing in all five patients.

Discussion: Overuse or abuse of empirical antibiotics poses a difficult challenge to the Health care system causing multi drug resistance. Parenteral CMS is expensive and causes renal toxicity. An 8 hourly regimen of colistimethate(CMS) (4.5million IU) for 7 days would cost about 70,000 INR, while local application of colistin+debridase costed about 5,000 INR for the same period without the additional renal toxicity. Addition of hydrolytic enzymes in the wound converts CMS to colistin by hydrolysis. This innovation can be adopted with other reserve antibiotics and can help healthcare professionals in low resource areas to provide source control and treat sepsis with MDR infected wounds cost effectively.

Keywords: Non healing wounds, Multi drug resistant bacteria, local application, Colistimethate sodium