Lorazepam Side effects, Drug Interactions, Administration

Lorazepam

Administration: oral, IM, IV (slow)

Pharmacokinetics          - absolute bioavailability ~ 90%

                        - rapidly conjugated to lorazepam glucuronide

                        - t1/2 1-2 hour (lorazepam)

                        - t1/2 ~ 18 hours (lorazepam glucuronide)

Side effects

CNS: confusion, dizziness, fatigue, memory impairment, disorientation, headache

CVS: hypotension

GI: N/V/D/C, dry mouth, dysphagia

Drug-drug interactions

+ Oral contraceptive = increase clearance rate of lorazepam

+ theophylline = antagonize sedative effect

+ scopolamine = increase incidence of hallucinations, irrational behaviour & sedation