Effects of etizolam and ethyl loflazepate on the P300 event-related potential in healthy subjects.
BACKGROUND
Benzodiazepines carry the risk of inducing cognitive impairments, which may go unnoticed while profoundly disturbing social activity. Furthermore, these impairments are partly associated with the elimination half-life (EH) of the substance from the body. The object of the present study was to examine the effects of etizolam and ethyl loflazepate, with EHs of 6 h and 122 h, respectively, on information processing in healthy subjects.


METHODS
Healthy people were administered etizolam and ethyl loflazepate acutely and subchronically (14 days). The auditory P300 event-related potential and the neuropsychological batteries described below were employed to assess the effects of drugs on cognition. The P300 event-related potential was recorded before and after drug treatments. The digit symbol test, trail making test, digit span test and verbal paired associates test were administered to examine mental slowing and memory functioning.


RESULTS
Acute administration of drugs caused prolongation in P300 latency and reduction in P300 amplitude. Etizolam caused a statistically significant prolongation in P300 latency compared to ethyl loflazepate. Furthermore, subchronic administration of etizolam, but not ethyl loflazepate, still caused a weak prolongation in P300 latency. In contrast, neuropsychological tests showed no difference.


CONCLUSIONS
The results indicate that acute administration of ethyl loflazepate induces less effect on P300 latency than etizolam.
Department of Psychiatry, Chiba University Graduate School of Medicine, Chiba, Japan. fukami@faculty.chiba-u.jp.
Goro
G
Fukami
Tasuku
T
Hashimoto
Yukihiko
Y
Shirayama
Tadashi
T
Hasegawa
Hiroyuki
H
Watanabe
Mihisa
M
Fujisaki
Kenji
K
Hashimoto
Masaomi
M
Iyo