[Effects of flunarizine on cerebral venous outflow and cerebral oxygen consumption].

1) Flunarizine (0.3 and 1 mg/kg, i.v.) and papaverine (1 mg/kg, i.v.) caused significant increases in cerebral blood flow and decreases in cerebral vascular resistance with concomitant increases in cerebrospinal fluid pressure, in spite of decreases in systemic blood pressure. The duration of these effects by flunarizine were longer than those by papaverine. 2) Heart rate increased markedly with papaverine, while it decreased with flunarizine only at a dose of mg/kg, i.v. Central venous pressure increased slightly and temporarily with flunarizine, but it was not changed with papaverine. 3) Cerebral arteriovenous oxygen difference decreased with either of the drugs at a a dose of 1 mg/kg, i.v. Meanwhile, cerebral oxygen consumption was not affected by flunarizine or papaverine. 4) Either of the drugs increased the PO2 of the cerebral venous blood temporarily and slightly, but significantly, as well as the end tidal CO2 concentration. These results suggested that flunarizine has a longer acting cerebral vasodilatating effect that papaverine does without any effect on the cerebral oxygen consumption.