IV Colistin for Pulmonary Exacerbations: Improving Safety and Efficacy

The purpose of this study is to find the safest and most effective way to administer IV antibiotics to treat acute pulmonary exacerbations (APEs) in patients with cystic fibrosis (CF) that are caused by pathogens, like Pseudomonas aeruginosa. This study will test the safety and effectiveness of two commonly prescribed IV antibiotics: tobramycin and colistin. Though regularly used, not much is known about how these drugs compare with each other in terms of their toxicities, both during short term treatment of an APE and after many treatment courses with these drugs over many years. There are currently no guidelines on the safest and most effective antibiotics to use when treating APEs. We will study kidney function, sputum cultures, and treatment outcomes in patients receiving routine administration of one of these two IV antibiotics. We will also test these outcomes in patients receiving a less frequent dosing schedule for IV colistin. The hope is that this new schedule for IV colistin, which is twice a day and adjusted based on blood and urine tests, will reduce harmful side effects, such as kidney damage, while still being a powerful treatment against CF microbial pathogens.