Carfilzomib is primarily used in the treatment of multiple myeloma, a type of blood cancer that affects plasma cells. It is specifically prescribed for patients who have not responded well to other treatments or have experienced a relapse. The drug works by inhibiting proteasomes, which are complexes that break down proteins in cells. By blocking this process, carfilzomib causes the accumulation of damaged proteins in cancer cells, leading to their death. It is often administered intravenously in combination with other medications, such as dexamethasone, to enhance its effectiveness. Due to its potent mechanism, it is crucial for healthcare providers to monitor patients for potential side effects, including cardiac issues, respiratory problems, and kidney dysfunction.