EEG profile of intravenous zolpidem in healthy volunteers.

Zolpidem is an imidazopyridine which binds specifically to the omega 1 receptor. Zolpidem demonstrated potent hypnotic activity at a dose of 10 mg. Pharmacodynamics and pharmacokinetics of zolpidem were studied after daytime administration in a randomised, double-blind, placebo-controlled, cross-over trial. Single doses of zolpidem (10 mg IV as a 3-min infusion and 20 mg orally) and placebo were firstly tested in 12 healthy young male volunteers. Two other doses (5 mg IV and orally) were then evaluated in 6 out of these 12 subjects. EEG (4 leads = Fp2-T4, Fp1-T3, T4-02 and T3-01), and Stanford Sleepiness Scale (SSS) were measured up to 5 h postdosing. Blood samples were also collected up to 24 h. The time course of the hypnotic activity of zolpidem, assessed by the score obtained on SSS, showed a similar profile whatever the route or the dose administered: slightly earlier onset after IV but sedative scores were reached at 30 min and the effect peaked between 1 and 1.5 h and lasted 4 h in both conditions. The EEG profile of zolpidem was characterised by a decrease of alpha activity and an increase in delta and in beta activity. The effect on beta activity was marked within the first hour and then disappeared. The time course of delta and alpha activities indicated a rapid onset (10 min after IV, 30 min after oral route) and a duration of 3-4 h. The amplitude of these relative EEG changes and their duration were independent of the route of administration and the dose administered. AUC and Cmax increased proportionally to the administered dose and elimination half life (2h), clearance and volume of distribution did not change according to the dose or the route of administration.(ABSTRACT TRUNCATED AT 250 WORDS)

EEG profile of litoxetine after single and repeated administration in healthy volunteers.

1. Litoxetine is a selective serotonin reuptake inhibitor with antidepressant activity in animal models and in depressed patients. 2. This double-blind, cross-over, placebo-controlled study was carried out in 12 healthy young male volunteers. The aim was to assess the EEG profile of litoxetine in parallel with its pharmacokinetics after a single dose or multiple administrations for 4 days (6 doses) of two dosages (10 mg and 25 mg). Spectral analysis of four EEG leads (F4-T4, F3-T3, T4-02 and T3-01) was done up to 12 h post-dose. 3. In single or multiple doses, litoxetine induced EEG changes characterised by a dose-related increase in fast beta energies, mainly beta 2, without any changes in slow waves (delta and theta). A slight reduction in alpha activity occurred only after repeated doses. 4. EEG changes occurred after a single oral administration and lasted at least 12 h with litoxetine blood concentrations ranging from 4 to 10 ng ml-1. With repeated administrations, the pharmacodynamic steady-state was achieved as the increase in beta 2 energies was the same before and 12 h post-dose. These effects occurred with litoxetine blood concentrations ranging from 3 to 7 ng ml-1 with the 10 mg dosage and from 8 to 18 ng ml-1 with the 25 mg dosage. The EEG profile did not change after 4 days of repeated administration, indicating that tolerance did not develop. 5. Cmax and AUC showed proportionality between the administered dosages of 10 and 25 mg.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of zolpidem on alertness and psychomotor abilities among aviation ground personnel and pilots.

The use of hypnotics to optimize rest periods during sustained operations could be of help to military personnel. Zolpidem, an imidazopyridine hypnotic, was evaluated for its residual effects on daytime wakefulness in 12 subjects belonging to ground air force personnel and 12 navy fighter pilots. In this controlled double blind crossover study, each subject randomly received zolpidem 10 mg, flunitrazepam 1 mg or placebo, in three separate sessions, 1 week apart at 10 p.m. or 1 a.m., respectively. The absence of residual effects after zolpidem intake was attested by subjective assessments, psychomotor tests (including a simulated flight), and EEG analysis showed that this hypnotic could be considered for operational use.