Clazosentan is primarily used to reduce the incidence of cerebral vasospasm following aneurysmal subarachnoid hemorrhage. It acts as an endothelin receptor antagonist, specifically targeting the ETA receptor, which plays a key role in vasoconstriction. By blocking this receptor, clazosentan helps maintain cerebral blood flow, potentially preventing delayed ischemic neurological deficits. It is administered intravenously in critical care settings, especially in neurointensive units, to improve outcomes in patients recovering from ruptured brain aneurysms. Clinical studies have shown its effectiveness in reducing vasospasm-related complications, though its impact on long-term functional recovery is still under investigation.