Discrimination of Mode of Action of Anxiolytics using an Integrated Computer Data Bank and Dynamic Brain Mapping (cns Effects of Diazepam and Lorazepam)

In a double-blind, placebo-controlled, crossover study, the CNS effects of intravenously administered diazepam and lorazepam were investigated in anxious subjects through the quantitative pharmaco-EEG (QPEEG) method. For up to 4 hours following administration the effects of each substance on brain function were measured using computer analyzed EEG recordings (CEEG) and a new technique called Dynamic Brain Mapping. The following observations were made: 1. Both active drugs produce statistically significant CNS effects as measured by CEEG changes. These changes were observed earlier with diazepam than with lorazepam. 2. Although both compounds are classified as anxiolytic by the routine computer EEG data base, the detailed brain mapping technology indicated that the CNS effects of diazepam and lorazepam were quantitatively and qualitatively different. 3. Clinical CNS side-effects (sedation) were seen more frequently with lorazepam than with diazepam. This was consistent with the EEG slowing producing properties of lorazepam. The EEG fast activity which is characteristic for all anxiolytics was established more with diazepam than lorazepam.