Prevention of experimental subarachnoid hemorrhage-induced intracranial arterial vasonecrosis with phosphodiesterase inhibitor phthalazinol (EG-626).

Experiments in monkeys have demonstrated that the chronic vasospasm and arterial injury reaction produced by subarachnoid blood injection can be prevented by treatment with the phosphodiesterase inhibitor phthalazinol. This protective effect, which is present even when the drug treatment is initiated after the subarachnoid blood injection, is presumed to occur because of the platelet inhibiting effect of phthalazinol.