Encephalotropic and psychotropic effects of intravenous buflomedil in the elderly: double-blind, placebo-controlled pharmaco-EEG and psychometric studies.

In a double-blind placebo-controlled study, the encephalotropic and psychotropic properties of intravenously administered buflomedil--a new vasoactive drug--were studied in 10 elderly volunteers in their 60s by means of quantitative EEG and psychometric analyses. At weekly intervals the patients received randomized (latin square design), single, intravenous doses of placebo, 50 mg, 100 mg and 200 mg buflomedil as well as 2000 mg piracetam as reference substance. EEG recordings and the monitoring of blood pressure, heart rate and side-effects were carried out at hours 0, 1, 2, 4, 6 and 8. Psychometric tests were performed at hours 0, 2, 4, 6 and 8. Computer-assisted spectral analysis of the EEG demonstrated that buflomedil exerted a significant effect on the central nervous system (CNS) as compared with placebo, characterized by a decrease of delta and theta, increase of alpha and alpha-adjacent beta activity as well as by an acceleration of the centroid of the alpha activity and also of the total activity. 2 g piracetam induced the same type of changes only at the end of the recording day. These quantitative EEG changes have been previously observed after several antihypoxidotic/nootropic drugs and indicate an improvement in vigilance in the sense of Head. Treatment-efficacy calculations demonstrated that 200 mg buflomedil was the most CNS-effective substance followed by 100 mg and 50 mg buflomedil and 2 g piracetam. Time-efficacy calculations showed that the encephalotropic effects were already marked in the 1st hour after i.v. application, decreased to a low in the 4th hour and subsequently increased again to reach a maximum in the 8th hour. In contrast, 2 g piracetam induced CNS changes which increased from the 1st throughout the 6th hour to show only a slight decline thereafter. The hysteresis between pharmacodynamic and pharmacokinetic findings is discussed. Psychometric investigations demonstrated that after 50 mg buflomedil i.v. there was a significant improvement as compared with placebo in cognitive function based on the Pauli test as well as an increase in correct reactions in the alphabetical reaction test. Doses of 100 mg buflomedil also produced an improvement in the Pauli test, attenuated errors in the reaction time task, improved complex reaction on the Vinnese Determinationsgerät, increased CFF but also errors in the concentration test.(ABSTRACT TRUNCATED AT 400 WORDS)