Fasudil Hydrochloride is primarily used as a vasodilator to treat cerebral vasospasm, a condition that occurs after subarachnoid hemorrhage. It works by inhibiting Rho kinase, which helps relax blood vessels and improve blood flow to the brain. This reduces the risk of ischemic complications and improves patient outcomes. Additionally, it is being investigated for its potential in treating other conditions such as pulmonary hypertension, glaucoma, and neurodegenerative diseases like Alzheimer's and Parkinson's. Its ability to modulate cellular signaling pathways also makes it a candidate for research in cancer therapy and cardiovascular diseases.