Drug-induced dyspnea versus cystic fibrosis exacerbation: a diagnostic dilemma.

Cystic fibrosis (CF) is a disease caused by a mutation in the cystic fibrosis transmembrane conductance regulator protein in the epithelial membrane, and affects at least 30,000 people in the USA. There are between 900 and 1000 new cases diagnosed every year. Traditionally, CF has been treated symptomatically with pancreatic enzymes, bronchodilators, hypertonic saline, and pulmozyme. In July 2015, the US Food and Drug Administration approved Orkambi (lumacaftor/ivacaftor), a combination drug that works on reversing the effects of the defective cystic fibrosis transmembrane conductance regulator protein. Orkambi and mucolytics decrease the viscosity of mucous secretions, leading to an accumulation of hypoviscous fluid in the alveoli, resulting in dyspnea. This presentation can be mistaken for an infective exacerbation. We present a case in which a young female with CF recently started on Orkambi therapy presented to her primary care physician with dyspnea and increased respiratory secretions and was admitted to the hospital for 2 weeks of intravenous and inhaled antibiotic therapy for a presumed CF exacerbation. We highlight this case to bring awareness and educate patients and clinicians of the side-effect profile of Orkambi therapy with an intent to avoid unnecessary hospitalizations, inpatient antibiotics, and other costly medical services.