Prescribing-label excerpts
Lorazepam
Reference for: Lorazepam. Source presentation: tablet. Source route: oral.
The source label presents its clinical-pharmacology findings together. These selected passages retain the source’s study context; the full label provides the complete discussion.
Clinical pharmacology
Studies in healthy volunteers show that in single high doses lorazepam has a tranquilizing action on the central nervous system with no appreciable effect on the respiratory or cardiovascular systems.
Lorazepam is readily absorbed with an absolute bioavailability of 90%. Peak concentrations in plasma occur approximately 2 hours following administration. The peak plasma level of lorazepam from a 2 mg dose is approximately 20 ng/mL.
The mean half-life of unconjugated lorazepam in human plasma is about 12 hours and for its major metabolite, lorazepam glucuronide, about 18 hours. At clinically relevant concentrations, lorazepam is approximately 85% bound to plasma proteins. Lorazepam is rapidly conjugated at its 3-hydroxy group into lorazepam glucuronide which is then excreted in the urine. Lorazepam glucuronide has no demonstrable central nervous system (CNS) activity in animals.
The plasma levels of lorazepam are proportional to the dose given. There is no evidence of accumulation of lorazepam on administration up to 6 months.
Studies comparing young and elderly subjects have shown that advancing age does not have a significant effect on the pharmacokinetics of lorazepam. However, in one study involving single intravenous doses of 1.5 to 3 mg of lorazepam injection, mean total body clearance of lorazepam decreased by 20% in 15 elderly subjects of 60 to 84 years of age compared to that in 15 younger subjects of 19 to 38 years of age.
Selected passages from the cited U.S. prescribing label. The studies concern the source product and populations named in each passage; they do not establish Walter-product bioequivalence, an approved indication, or the kinetics of another fixed combination. Tables and the full prescribing information remain available in the source.
Source: DailyMed: Lorazepam — tablet
Reference accessed . Label revision: 2026-07-15.
