An absolute must in clinico-pharmacological research: pharmaco-electroencephalography, its possibilities and limitations.

During drug development effects on blood cells, metabolism or function of heart and circulation are routinely examined. In case there is evidence of influence on such systems, examinations in clinical pharmacology are done. For the organ central nervous system the same rules should be followed, independently whether a substance is primarily a psychotropic drug or developed for other indications. Besides pharmacopsychological procedures pharmacoelectroencephalography is the most sensitive method to describe drug induced changes on brain function of humans. In event related research (e.g. evoked potentials) it is easier to form hypotheses for the mechanism of reaction after stimulation. About the validity of spontaneous cortical activity, like scalp recorded EEG we have little knowledge. However, a single signal of the spontaneous activity is analyzed into several components, each of which can be influenced differently by various drugs. Important areas of pharmacoelectroencephalography are: 1) Determination of CNS effects on a functional level; judgement whether a pharmacon has a potential for influencing CNS function in comparison to placebo. 2) Characterization of CNS-effects; determination of vigilance changes and classification of the profile in comparison to the EEG-effects of standards. 3) Determination of dose/efficacy and time/efficacy relations; description of kinetic data based on an effect-parameter, in contrast to blood levels; comparison of different galenic formulations; determination of onset and duration of effects; etc. 4) Determination of sleep-wake rhythms; measurement of influence on sleep/waking behaviour in the sleep laboratory or under vigilance controlled conditions during daytime.(ABSTRACT TRUNCATED AT 250 WORDS)