Antihypoxidotic and nootropic drugs: proof of their encephalotropic and pharmacodynamic properties by quantitative EEG investigations

Abstract

1. 1. In several double-blind placebo-controlled studies the encephalotropic and pharmacodynamic properties of antihypoxidotics and nootropics such as dihydroergotoxine, nicergoline, Instenon forte (a hexobendine-combination), cinnarizine, isoxsuprine, pirazetam and etirazetam- a new pirazetam analogue — were investigated by means of quantitative EEG analysis in normal young and geriatric subjects. 2. 2. Power pectral density analysis of the EEG demonstrated after the ergot alkaloids Hydergine R and nicergoline as well as after Instenon forte statistically significant changes as compared with placebo. The latter were characterized by an increase in alpha and slow beta activity as well as by a decrease in delta and theta activity, which indicates an increase in vigilance. 3. 3. Pirazetam and the new pirazetam analogue etirazetam — produced a significant increase in beta activity as well, while alpha activity was augmented or attenuated according to the given dosage. After chronic administration of UCB 6474 and especially after high doses, an increase in theta activity was observed. Psychometric tests showed also activating qualities in low doses and slight sedative properties in high doses. 4. 4. Cinnarizine and isoxsuprine produced in the R-EEG different alterations typified by an increase of slow and decrease of fast waves. 5. 5. Time-efficacy and dose-efficacy relationships in various EEG parameters give valuable information about the pharmacodynamics of such substances in man already at an early stage of drug development.