LOREEV XR pharmacokinetics are dose proportional over the dose range of 1 mg to 3 mg. Steady-state plasma concentrations are typically achieved after 5 days of once-daily administration.
At steady-state, the mean area under concentration curve (AUCTau), the mean peak plasma concentration (Cmax), and the mean minimum plasma concentration (Cmin) of lorazepam following LOREEV XR 3 mg once-daily administration was 694 ng*h/mL, 35 ng/mL and 25 ng/mL, respectively. AUCTau, Cmax, and Cmin of lorazepam from lorazepam tablets following 1 mg, three-times daily administration were 765 ng*h/mL, 41 ng/mL and 29 ng/mL, respectively.
Absorption
Following a single 3 mg dose of LOREEV XR under fasted conditions, the median time to attain Cmax (Tmax) is 14 hours, with a range of 7 to 24 hours.
Effect of Food
Administration of LOREEV XR with a high-fat and high calorie meal did not have a significant effect on exposure of LOREEV XR. However, median Tmax of lorazepam delayed by approximately 2 hours.
LOREEV XR administered under fasted conditions after sprinkling the entire contents onto one-tablespoon (15 mL) of applesauce did not significantly affect exposure and Tmax of lorazepam.
Distribution
Following a single 3 mg dose of LOREEV XR under fasted conditions, the mean apparent volume of distribution is approximately 117 L. At clinically relevant concentrations, lorazepam is approximately 85% bound to plasma proteins.
Elimination
Oral mean plasma clearance (CL/F) is about 72 mL/min in adults following a single 3 mg dose of LOREEV XR and the mean elimination half-life of lorazepam is approximately 20.2 ± 7.2 hours.
Metabolism
Lorazepam is conjugated at its 3-hydroxy group in the liver into lorazepam glucuronide, which has no demonstratable CNS activity in animals.
Excretion
Lorazepam glucuronide is excreted in the urine.
Specific Populations
Geriatric Patients
Studies comparing young and elderly subjects have shown that advancing age does not have a significant effect on the pharmacokinetics of lorazepam tablets. However, a 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. The clinical significance of the decrease in mean total body clearance of lorazepam injection in geriatric patients is unknown.
Patients with Hepatic Impairment
No pharmacokinetic studies were conducted with LOREEV XR in patients with hepatic impairment.
Patients with Renal Impairment
No pharmacokinetic studies were conducted with LOREEV XR in patients with renal impairment. Lorazepam is poorly dialyzable. Lorazepam glucuronide, the inactive metabolite, may be highly dialyzable.
Drug Interaction Studies
Concurrent administration of lorazepam with valproate, an inhibitor of UGT, results in increased plasma concentrations and reduced clearance of lorazepam [see Dosage and Administration (2.5), Drug Interactions (7)].
Concurrent administration of lorazepam with probenecid, an inhibitor of UGT, may result in a more rapid onset or prolonged effect of lorazepam due to increased half-life and decreased total clearance [see Dosage and Administration (2.5), Drug Interactions (7)].
Alcohol: An in vitro study showed significant increases of lorazepam release from LOREEV XR capsules at 2 hours with approximately 91-95% and 37-42% of the drug release in the presence of 40% and 20% alcohol, respectively [see Drug Interactions (7)]. Effects of 5% and 10% alcohol on drug release were not significant at 2 hours. There is no in vivo study conducted for the effect of alcohol on drug exposure.