IV Colistin for Pulmonary Exacerbations: Improving Safety and Efficacy

April 8, 2026 updated by: National Jewish Health
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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
51

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Colorado
      • Denver, Colorado, United States, 80206
        • National Jewish Health

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Male or female ≥ 18 years of age at Visit 1.

  2. Documentation of CF diagnosis as evidenced by one or more clinical features consistent with the CF phenotype and one or more of the following criteria:

    • Sweat chloride equal or greater than 60 mEq/L by quantitative pilocarpine iontophoresis test.
    • Two well-characterized mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene
    • Abnormal nasal potential difference (NPD) as measured by a change in NPD in response to a low chloride solution and isoproterenol of less than -5 mV.
  3. Documentation of the presence of an acute pulmonary exacerbation, based on CF Foundation guidelines, as diagnosed by a faculty member of the Denver Adult CF Program.
  4. Respiratory culture(s) demonstrating evidence of Pseudomonas aeruginosa or Achromobacter species airway infection.
  5. Subject is able to produce sputum, undergo phlebotomy, and provide written consent.
  6. The subject's treating physician has determined that they should receive either tobramycin or colistin intravenously as one of the designated agents for their APE treatment. Subjects who are able to receive either tobramycin or colistin as part of their antibiotic regimen will be randomized into one of three arms. If a treating physician deems that a subject cannot receive tobramycin due to vestibular toxicity, ototoxicity or bacterial resistance, the subject will be randomized to either standard or PK-adjusted colistin.

Exclusion Criteria:

  1. Concomitant administration of bactrim (due to effects on creatinine).
  2. Concomitant administration of inhaled colistin for patients in the colistin PK arm, as this will create inaccuracies in colistin sputum concentration measurements.
  3. Patients being treated for B. cepacia, due to colistin resistance by the pathogen.
  4. Presence of chronic renal insufficiency, with abnormal baseline creatinine >1.2mg/dL.
  5. Presence of a condition or abnormality that in the opinion of the investigator would compromise the safety of the patient or the quality of the data.
  6. Inability to perform reproducible spirometry.
  7. Inability to expectorate sputum. -

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Standard colistin arm
Subjects initially receive IV colistin 2.5 mg/kg/d divided into three times daily (TID) dosing. Subjects receiving colistin will undergo a 2 day up-titration of dose to an ultimate dose of 4-5 mg/kg/day, for a total treatment of 14 days. The drug is infused over 30 minutes on a TID dosing schedule.
Drug: Colistin
Active Comparator: Modified colistin arm
Subjects receiving IV colistin undergo a 2 day up-titration to a maximum dose of 5 mg/kg/day, divided into twice daily (BID) dosing, for a total treatment of 14 days. The drug is infused over 30 minutes BID. Steady state plasma concentrations on day 3 of therapy (on 2nd- 3rd dose once at goal dosing) will be measured; specifically, colistin peak (30 minutes after infusion), midpoint (6 hour) and trough (30 minutes prior to next infusion).
Drug: Colistin
Active Comparator: Standard tobramycin arm
Subjects receive IV tobramycin 8-10 mg/kg/day with once daily dosing for 14 days. Peaks and troughs are drawn with the second dose of tobramycin, and the drug is infused over 30 minutes
Drug: Tobramycin

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Absolute Change in Forced Expiratory Volume at One Second (FEV1) % Predicted Between Study Arms With Acute Pulmonary Exacerbation (APE) Treatment
Time Frame: up to 14 days, from beginning to end of APE treatment
absolute change in forced expiratory volume at one second (FEV1) % predicted, or percent predicted FEV1, between study arms with acute pulmonary exacerbation (APE) treatment
up to 14 days, from beginning to end of APE treatment
Rate of Occurrence of the Development of Acute Kidney Injury (AKI) During APE Treatment
Time Frame: up to 14 days, from beginning to end of APE treatment
up to 14 days, from beginning to end of APE treatment

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Differences in Occurrences of Neurotoxicity and Ototoxicity Related Side Effects Between Study Arms as Reported by Treating Physician(s)
Time Frame: up to 14 days, from beginning to end of APE treatment
absolute occurrences of adverse event rates are being compared between treatment groups using logistic regression, adjusting for age, co-administration of medications such as vancomycin and trimethoprim-sulfamethoxazole, baseline FEV1, admits in the previous year, and diagnosis of CF related diabetes (CFRD) as covariates.
up to 14 days, from beginning to end of APE treatment
Longitudinal Differences in Exacerbation Rates Between Tobramycin and Colistin Use as Seen in Readmission Rate
Time Frame: from the beginning of APE treatment to 12 months after APE treatment
time to next hospital admission for pulmonary exacerbation measured in days when comparing of different antibiotic therapies
from the beginning of APE treatment to 12 months after APE treatment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
National Jewish Health

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Milene Saavedra, MD, National Jewish Health

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 26, 2016

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 10, 2020

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 22, 2021

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 12, 2016

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 26, 2016

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 29, 2016

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 28, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 8, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2023

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • SAAVED15A0

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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