Duration of Antibiotics in Infective Exacerbations of Cystic Fibrosis

Inclusion Criteria: * 16 years or older * Diagnosis of Cystic Fibrosis * Presenting with Infective exacerbation Exclusion Criteria: * Unable to give consent * Allergy to study medications * Intolerance of aminoglycoside antibiotics * Pseudomonas resistant to study antibiotics * On the active transplant list or FEV1\<20% predicted * Pregnancy/breast-feeding * Co-existent ABPA requiring a change in treatment * Co-existent mycobacterial infection * A previous participant in the study