Effect of edaravone on cerebral vasospasm following experimental subarachnoid hemorrhage.

The effect of the free radical scavenger edaravone on experimental cerebral vasospasm following subarachnoid hemorrhage (SAH) was investigated in a canine double hemorrhage model. Changes in the diameter of the basilar artery were assessed by serial angiography. The diameter ratio at day 7 was calculated as the percent of the basilar artery diameter of a given angiogram with respect to that of its control (day 0). The diameter ratios for the basilar artery following SAH in the control and vehicle-treated groups were 49.7% +/- 3.9% (mean +/- SEM) and 50.1% +/- 1.7%, respectively. Edaravone was administered either by continuous intravenous injection for 7 days or by bolus injection for 7 days. Continuous administration of edaravone (1 mg/kg/hr or 10 mg/kg/hr) significantly attenuated the narrowing of the basilar artery following SAH. The diameter ratios in these groups were 71.3% +/- 3.6% (1 mg/kg/hr) and 75.7% +/- 1.7% (10 mg/kg/hr). Bolus administration of edaravone (3 mg/kg, every 12 hours) reduced the arterial narrowing following SAH. The diameter ratio on day 7 was 60.1% +/- 3.3%, but the difference was not significant. These findings suggest that edaravone is effective in preventing cerebral vasospasm following SAH.