The effect of ivacaftor in adolescents with cystic fibrosis (G551D mutation): an exercise physiology perspective

Pediatr Phys Ther. 2014 Winter;26(4):454-61. doi: 10.1097/PEP.0000000000000086.


Purpose: The purpose of this report was to evaluate the influence of 12 weeks of ivacaftor treatment on the aerobic function of 2 teenage patients with cystic fibrosis (CF; ΔF508/G551D) using a maximal cardiopulmonary exercise test.

Summary of key points: One patient, with relatively mild disease, demonstrated no clinically meaningful changes in maximal oxygen uptake ((Equation is included in full-text article.)O2max). However, in the second case, with more established lung disease on imaging, (Equation is included in full-text article.)O2max improved by approximately 30%, an improvement out of proportion with early lung function changes. This improvement resulted from increased muscle oxygen delivery and extraction.

Statement of conclusions: Cardiopulmonary exercise testing can monitor the extent and cause(s) of change following interventions such as ivacaftor, with the potential to identify functional changes independent from spirometry indices.

Recommendations for clinical practice: Cardiopulmonary exercise testing represents an important and comprehensive clinical assessment tool, and its use as an outcome measure in the functional assessment of patients with CF is encouraged.

Publication types

  • Case Reports

MeSH terms

  • Adolescent
  • Aminophenols / administration & dosage
  • Aminophenols / adverse effects
  • Aminophenols / therapeutic use*
  • Body Weights and Measures
  • Cystic Fibrosis / drug therapy*
  • Cystic Fibrosis / rehabilitation*
  • Cystic Fibrosis Transmembrane Conductance Regulator / agonists*
  • Exercise Test*
  • Female
  • Humans
  • Male
  • Quinolones / administration & dosage
  • Quinolones / adverse effects
  • Quinolones / therapeutic use*
  • Respiratory Function Tests


  • Aminophenols
  • Quinolones
  • Cystic Fibrosis Transmembrane Conductance Regulator
  • ivacaftor