The PNEUMONIA Times
Aerosolized Colistin for Ventilator-Associated Pneumonia
One of the Polymyxins, known as colistin, are currently used as a last-resort treatment of multidrug-resistant (MDR) bacterial infections caused by Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae.
Colistimethate sodium is a prodrug which is broken down to colistin in the body. Be cautious when taking colistin as it may potentially lead to a case of fatal airway irritation upon ingestion.
Inhaled colistin were determined in patients with ventilator-associated tracheobronchitis because P aeruginosa, A baumannii, or K pneumoniae are susceptible only to polymyxin. Patients received 1 million IU of nebulized colistimethate sodium (30 mg colistin base) every 8 hours for 7 days. Cure was achieved in 16 of 20 patients, but colistin concentrations in epithelial lining fluid declined below the MIC values by 8 hours in 8 out of 20 patients. Patients with pathogens susceptible to β-lactams were included as a control group and treated with intravenous antibiotics for 14 days. Patients with MDR organisms were treated with nebulized colistimethate sodium 5 million IU (150 mg colistin base) every 8 hours for 7-19 days. In the nebulized group, 67% were clinically cured at the end of treatment compared with 66% in the control arm treated with intravenous β-lactams.
The optimum dose of nebulized colistin for patients with MDR pathogens is not fully clear due to a lack of randomized trials, but higher-dose regimens have been used successfully without significantly increasing the risk for nephrotoxicity.
References:
- http://www.medscape.com/viewarticle/848388
- Valachis A, Samonis G, Kofteridis DP (2015). The role of aerosolized colistin in the treatment of ventilator-associated pneumonia: a systematic review and metaanalysis. Pubmed. Retrieved 29th December 2015, from <http://www.ncbi.nlm.nih.gov/pubmed/25493971>