With the aid of the pharmaco-EEG, essential information can be obtained in early drug development regarding CNS penetration and efficacy of new substances as follows:
- Evidence for substance penetration (bioavailability) in the CNS on the basis of PD changes. In addition to the classic PK parameters (e.g., tmax, Cmax, AUC and t½), EEG/ERP parameters can be used to demonstrate time- and dose-effect correlations.
- Proof of CNS effects of a substance by comparison of quantitative EEG (qEEG/ERP) changes between pre- and post-dose measurements.
- Characterization of psychotropic properties of a substance by comparison with psychotropic class effects of marketed drugs. Classic psychotropic drugs show typical pharmaco-EEG profiles, thus allowing assignment of new substances in many cases.
- Determination of new substance’s therapeutic window. The dose at which a new substance can be statistically distinguished from placebo, and at which it displays a psychotropic effect in comparison with a reference preparation, is often a therapeutically effective dose.
- Proof of adverse CNS effects of non-psychotropic substances (e.g., sedation produced by anti-hypertensive drugs or anti-histamines, changed convulsion threshold due to antibiotics).
- Determination of the bioequivalence of two different galenic dosage forms by quantitative comparison of CNS changes.