White or almost white, hygroscopic, crystalline powder.
용도
Sedativehypnotic.
정의
ChEBI: The hemitartrate salt of zolpidem.
Pharmacokinetics
Zolpidem exhibits a high selectivity for the α1 subunit. Its good bioavailability of 72% and rapid onset of action
of approximately 1.4 hours following oral absorption can be attributed to its weak base (pKa = 6.2) and high
lipophilicity (mlog P = 3.85). Its pharmacokinetic profile is characterized by rapid absorption from the
gastrointestinal tract and a short elimination half-life because of rapid oxidative metabolism to inactive
carboxylic acid metabolites. Zolpidem undergoes CYP3A4 (major), CYP2DG, and CYP2D6
hydroxylation of the aryl methyl groups, followed by further oxidation by aldehyde
dehydrogenase to the ionic carboxylic acids, which are readily eliminated in the urine. Zolpidem
demonstrates linear (dose-proportional) kinetics in the dose range of 5 to 20 mg. Although protein binding was
90%, no drug accumulation was observed following nightly dosing with 20-mg zolpidem tartrate tablets for 2
weeks. Food can prolong the time to peak concentration from 1.4 to 2.2 hours without affecting the half-life.
These results suggest that for faster sleep onset, zolpidem should not be administered with or immediately after
a meal. In the elderly, the dose should be 5 mg, because the elimination half-life is increased by 50% (from ~2
to ~3 hours). No accumulation was observed in elderly subjects following nightly oral dosing of 10 mg for 1
week. In patients with hepatic insufficiency, the plasma concentration doubled with an increase in the
elimination half-life from approximately 2 to approximately 10 hours (range, 4–25 hours). Therefore, dosing
should be modified in patients with hepatic insufficiency. No dosage adjustment should be necessary in patients
with compromised renal function. Zolpidem is not hemodialyzable, but it does cross the placenta and into breast
milk. Because of its longer elimination half-life (when compared to zaleplon), it may be preferred when sleep
maintenance is a primary concern.
