[Correlation of the clinical pharmacological action of a single dose of fenazepam with the EEG dynamics and pharmacokinetics].

Interaction between the clinical, EEG-effects and phenazepam concentration in the blood was studied in 111 patients with neurotic disorders after intake of the test drug dose (2 mg) administered singly and on the 14th day of the treatment. It was established that EEG changes commonly induced by benzodiazepines supervene primarily within the interval of 1 to 3 h after a single intake which correlates with the maximal degree of the tranquilizing, somnolent and myorelaxant drug action. It was demonstrated that the clinical and EEG-effects occur before attainment of the maximal phenazepam concentration and then become less potent, with preservation of the high blood drug level. Intake of the test dose during the treatment course is characterized, as compared with the effect of a single intake, by less marked clinical action of the drug and the lack of significant changes on the EEG and in the blood phenazepam concentration.