Beneficial effects of moxonidine on cerebral vasospasm after experimental subarachnoid hemorrhage

This study was designed to examine the efficacy of moxonidine, a centrally acting antihypertensive agent that is a selective ligand for I1-imidazoline sites, in a rabbit cerebral vasospasm model. Twenty-four white, male New-Zealand rabbits weighing 2500-3200 gr. were randomly allocated into three groups as group 1= control group, group 2=subarachnoid hemorrhage (SAH) alone group, and group 3=SAH + moxonidine (treatment) group. Cerebral angiography was performed to all rabbits before (Day=0, basal angiography) and 72 hours after the induction of SAH. Intraperitoneal moxonidine (0.5 mg/kg) treatment was started after the induction of SAH and continued once a day for 72 hours in the treatment group. No statistically significant difference was determined in basal angiographic luminal diameter of the basilar artery between groups (p > 0.005). After SAH, the follow-up angiographic basilar artery luminal diameter significantly changed in treatment group when compared with the SAH alone group (p < 0.001). The pathologically examined basilar artery luminal area was different between these groups (p < 0.005). Moxonidine treatment as a centrally acting antihypertensive agent was found to be very beneficial in the treatment of vasospasm by increasing the angiographic diameter and the pathologic luminal area and reducing muscular wall thickness.