Lixivaptan is primarily used in the treatment of hyponatremia, a condition characterized by low sodium levels in the blood. It works as a vasopressin receptor antagonist, helping to increase sodium levels by promoting the excretion of water without significant loss of electrolytes. This makes it particularly useful in managing hyponatremia associated with conditions like heart failure, liver cirrhosis, and syndrome of inappropriate antidiuretic hormone secretion (SIADH). Its targeted action on the kidneys helps restore fluid balance, improving patient outcomes and reducing symptoms such as confusion, seizures, and fatigue. Lixivaptan is often considered when other treatments are ineffective or unsuitable, offering a valuable option for managing this complex condition.