Clinical pharmacokinetics of lorazepam: a review.
The clinical pharmacokinetics of lorazepam, a 3-hydroxy, 1,4-benzodiazepine, indicate that it is rapidly and readily absorbed, reaching peak concentrations in the blood proportional to the dose approximately 2 hours after oral administration. Blood levels decline thereafter, with an elimination half-life of about 12 hrs. Conjugation with glucuronic acid to form inactive lorazepam glucuronide is the major metabolic pathway. Seventy (70) to 75% of the administered dose is excreted as the glucuronide conjugate in the urine. On multiple-dose regimens, steady state blood levels directly proportional to the daily dose occur within 2--3 days and are maintained after several months of continuous treatment. The active drug and the glucuronide conjugate are completely eliminated from the blood within 1 week following the last dose.
D000284:Administration, Oral; D000367:Age Factors; D014151:Anti-Anxiety Agents / Q000378:metabolism*; D002849:Chromatography, Gas; D004305:Dose-Response Relationship, Drug; D005965:Glucuronates / Q000378:metabolism; D006801:Humans; D007273:Injections, Intramuscular; D007275:Injections, Intravenous; D007676:Kidney Failure, Chronic / Q000378:metabolism; D007700:Kinetics; D008140:Lorazepam / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism* / Q000652:urine; D008657:Metabolic Clearance Rate; D011485:Protein Binding
D014151:Anti-Anxiety Agents; D005965:Glucuronates; D008140:Lorazepam