Effects of some cerebrovasodilators on the anti-anoxic activity of indeloxazine hydrochloride [(+/-)-2[(inden-7-yloxy)methyl]morpholine hydrochloride, YM-08054] with cerebral metabolic enhancing activity, were observed in mice. Oral administration of both indeloxazine (10 mg/kg) and each of the cerebral vasodilators, such as nicardipine (10 mg/kg), cinepazide (100 mg/kg), ifenprodil (1 mg/kg), pentoxyfylline (1 mg/kg) and vinpocetine (10 mg/kg) significantly prolonged the survival time of mice subjected to anoxia, without affecting pentobarbital-induced sleeping time. The effect of indeloxazine was potentiated by a sub-effective dose of the cerebral vasodilators. The effect of a combined treatment may be due to the cerebral metabolic enhancing and vasodilating activities of both drugs. These results demonstrate the beneficial pharmacological properties of the combined treatment with indeloxazine and cerebrovasodilator and encourage combination therapy for the treatment of organic brain syndromes.