title: Temporal variations of lorazepam pharmacokinetics.
abstract: Lorazepam pharmacokinetics were evaluated in eight healthy male and eight healthy female subjects after a single 3.5 mg oral dose. This randomized crossover study consisted of a morning dose (7:00 a.m.) or an evening dose (7:00 p.m.) separated by one week. While no consistent temporal changes in any parameter characterizing elimination of lorazepam were observed, absorption constant rate (Ka) and absorption half-life (t1/2a) were significantly modified by the hour of administration, the drug being more rapidly absorbed after the morning (t1/2a = 0.52 +/- 0.11) than after the morning trial (t1/2a = 1.18 +/- 0.26, p less than 0.05). Daily differences in pharmacokinetic parameters observed in this work suggest the need for taking in account the hour of administration during its pharmacokinetics determination.
mesh_terms: D000328:Adult; D002849:Chromatography, Gas; D005260:Female; D006801:Humans; D007700:Kinetics; D008140:Lorazepam / Q000097:blood / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D013997:Time Factors
chemical_list: D008140:Lorazepam