Ivacaftor is primarily used in the treatment of cystic fibrosis, specifically for patients who have certain mutations in the CFTR gene, such as the G551D mutation. It works by enhancing the function of the defective CFTR protein, which helps improve the flow of salt and fluids in and out of cells. This leads to better hydration of mucus in the lungs and other organs, reducing the risk of infections and improving lung function. Patients taking Ivacaftor often experience fewer respiratory symptoms, a decrease in the frequency of pulmonary exacerbations, and an overall improvement in quality of life. It is typically administered orally and is often used as part of a comprehensive treatment plan that includes other therapies tailored to the individual's needs.