Studying How Antibiotics Work in Cystic Fibrosis Patients Using ElexacaftorTezacaftorIvacaftor ETI During Lung Infection Treatments

What this Trial Is About

Cystic fibrosis CF causes changes in how the body processes antibiotics, affecting absorption, distribution, metabolism, and elimination. These changes historically led to higher antibiotic doses to reach effective concentrations and improve lung health. The introduction of the triple combination drug elexacaftortezacaftorivacaftor ETI has greatly improved lung function, nutrition, inflammation, and quality of life in CF patients, while also altering respiratory infections and reducing lung flare-ups. This observational study tracks intravenous antibiotic levels in adolescents and adults with CF who are receiving ETI during lung exacerbations needing antibiotic treatment. Routine antibiotic therapy and drug monitoring follow standard care practices, with no additional interventions assigned. The study compares antibiotic concentrations to current recommended targets to understand how ETI may affect antibiotic dosing needs. Participants will be monitored through blood tests to measure antibiotic levels on day 3 of therapy, along with clinical assessments of weight, temperature, appetite, fatigue, breathing difficulty, sputum amount and quality, kidney function, and inflammation at various points during treatment. Treatment adherence and any side effects will also be tracked over about 14 days. The study aims to help optimize antibiotic dosing in CF patients treated with ETI while minimizing side effects.

Pharmacokinetics of Antibiotics in Patients With Cystic Fibrosis Trated With Elexacaftor/Tezacaftor/Ivacaftor (ETI)