OBJECTIVE: To examine the effect of cytochrome P450 (CYP) 2C19 activity on the single-dose pharmacokinetics and pharmacodynamics of etizolam. METHODS: The subjects were 21 healthy Japanese volunteers. The two mutated alleles (CYP2C19*2 and CYP2C19*3) causing absent CYP2C19 activity were identified by a polymerase chain reaction method. Twelve subjects were extensive metabolizers (EMs) with no or one mutated allele, and nine subjects were poor metabolizers (PMs) with two mutated alleles. The subjects received a single oral 1-mg dose of etizolam, and blood samplings and evaluation of psychomotor function were conducted up to 24 h after dosing. RESULTS: The PMs had significantly larger total area under the plasma concentration-time curve (287+/-74 vs 178+/-122 ng.h/ml, p<0.05) and longer elimination half-life (14.8+/-4.2 vs 10.5+/-3.9 h, p<0.05) of etizolam than the EMs. The area under the score-time curve from 0 to 8 h of the Stanford Sleepiness Scale was significantly larger in the PMs than in EMs (28.9+/-5.2 vs 22.9+/-6.9 score.h, p<0.05). CONCLUSION: The present study suggests that the single-dose pharmacokinetics and pharmacodynamics of etizolam are influenced by polymorphic CYP2C19 activity.
OBJECTIVE: To examine the effect of cytochrome P450 (CYP) 2C19 activity on the single-dose pharmacokinetics and pharmacodynamics of etizolam. METHODS: The subjects were 21 healthy Japanese volunteers. The two mutated alleles (CYP2C19*2 and CYP2C19*3) causing absent CYP2C19 activity were identified by a polymerase chain reaction method. Twelve subjects were extensive metabolizers (EMs) with no or one mutated allele, and nine subjects were poor metabolizers (PMs) with two mutated alleles. The subjects received a single oral 1-mg dose of etizolam, and blood samplings and evaluation of psychomotor function were conducted up to 24 h after dosing. RESULTS: The PMs had significantly larger total area under the plasma concentration-time curve (287+/-74 vs 178+/-122 ng.h/ml, p<0.05) and longer elimination half-life (14.8+/-4.2 vs 10.5+/-3.9 h, p<0.05) of etizolam than the EMs. The area under the score-time curve from 0 to 8 h of the Stanford Sleepiness Scale was significantly larger in the PMs than in EMs (28.9+/-5.2 vs 22.9+/-6.9 score.h, p<0.05). CONCLUSION: The present study suggests that the single-dose pharmacokinetics and pharmacodynamics of etizolam are influenced by polymorphic CYP2C19 activity.
Authors: H Furukori; K Otani; N Yasui; T Kondo; S Kaneko; R Shimoyama; T Ohkubo; T Nagasaki; K Sugawara Journal: Neuropsychopharmacology Date: 1998-05 Impact factor: 7.853
Authors: K Araki; N Yasui-Furukori; T Fukasawa; T Aoshima; A Suzuki; Y Inoue; T Tateishi; K Otani Journal: Eur J Clin Pharmacol Date: 2004-07-01 Impact factor: 2.953
Authors: N Yasui; T Kondo; K Otani; H Furukori; S Kaneko; T Ohkubo; T Nagasaki; K Sugawara Journal: Psychopharmacology (Berl) Date: 1998-10 Impact factor: 4.530