Ivacaftor is a medication used in the management of cystic fibrosis, specifically targeting patients with specific mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. It works by enhancing the function of defective CFTR proteins, thereby improving salt and water movement across cell membranes. This mechanism helps in alleviating the symptoms associated with cystic fibrosis, a genetic disorder that affects the respiratory, digestive, and reproductive systems.