Ivacaftor benzenesulfonate is primarily used in the treatment of cystic fibrosis, specifically targeting the underlying cause of the disease in patients with certain genetic mutations. It works by enhancing the function of the defective CFTR protein, which is responsible for regulating the flow of salt and fluids in and out of cells. This improvement in protein function helps to reduce the buildup of thick, sticky mucus in the lungs and other organs, thereby alleviating symptoms such as breathing difficulties and recurrent infections. It is often prescribed for patients with the G551D mutation or other responsive mutations, significantly improving lung function and overall quality of life. Additionally, it can be used in combination with other cystic fibrosis therapies to achieve better clinical outcomes.