This study is for people with cystic fibrosis (CF), a lung disease that makes it hard to breathe. When CF gets worse, it's called a pulmonary exacerbation (PEx), which means breathing problems need special medicine called antibiotics. Doctors want to know if using one type of antibiotic, called beta-lactams (β-lactams), is as good as using two types, β-lactams and another called aminoglycosides, like tobramycin. The study will check how well these treatments work in improving lung function over a 14-day period.

Key Points:

• The study lasts 28 days, with main visits on Day 1 and Day 28.
• No cost for treatment, but you need to be available for study visits.
• Participants must be 6 years or older, have CF, and be ready for a 14-day antibiotic treatment.

Before joining, you should not have any kidney problems or recent serious lung issues. Also, you shouldn't have used certain new medicines or treatments in the last few weeks.