[Effect of dilazep on experimental vasospasm--evaluation of angiographical vasospasm and cerebral blood flow]

The effects of dilazep dihydrochloride on angiographic vasospasm and regional cerebral blood flow after subarachnoid hemorrhage were evaluated in double hemorrhage canine model. Severe angiographic vasospasm of basilar artery (percent reduction of intra-luminal diameter; 52.4%) was shown in untreated dogs. Daily intra-venous administration of dilazep (0.3 mg/kg for one hour) significantly inhibited angiographic vasospasm (percent reduction of intra-luminal diameter; 33.2%, p less than 0.05). Dilazep had a marked vasodilatory effect even in severe vasospasm in untreated dogs, and had a tendency to increase cerebral blood flow of the cerebral cortex in spite of reduced blood pressure. From these characteristics of action, intra-venous administration of dilazep would be useful agent for the treatment of cerebral vasospasm after subarachnoid hemorrhage.