Difelikefalin is primarily used in the treatment of chronic kidney disease-associated pruritus (CKD-aP), a condition characterized by severe itching in patients undergoing dialysis. It works by targeting kappa opioid receptors in the nervous system, reducing the sensation of itch and improving the quality of life for affected individuals. The drug is administered intravenously, typically during dialysis sessions, ensuring consistent and effective relief. Its selective action on peripheral kappa receptors minimizes central nervous system side effects, making it a safer option for long-term use in this patient population.