Lorazepam

Description

Lorazepam is a benzodiazepine sedative used for reduction of anxiety or as an adjunct for anesthesia.

Indications

• Anxiety disorders (only up to 4 months, to minimize chances of dependency)
• Anxiety-related insomnia
• Anesthesia premedication to relieve anxiety or induce sedation and amnesia
• Status epilepticus
• Rapid tranquilization of agitated patients
• Alcohol withdrawal
• Panic disorder
• Delirium
• Chemotherapy-associated nausea
• Psychogenic catatonia

Administration Routes

• Oral
• Intravenous (IV)
• Intramuscular (IV)

Side Effects

• Local injection site reaction
• Ataxia
• Dizziness
• Respiratory depression
• Paradoxical reaction
• Confusion
• Seizures
• Tachycardia
• Hypotension
• Fainting
• Withdrawal symptoms if abruptly discontinued after long-term use
• Cognitive deficits
• Behavioral changes
• Difficulty speaking clearly
• Constipation

Dosage

For anxiety disorder:

• 30 to 45 μg/kg orally, up to 3 times daily

For insomnia:

• 10 to 30 μg/kg orally at bedtime

Premedication for anesthesia:

• 50 μg/kg IM administered 2 hours before surgery
• or, 45 μg/kg IV administered 15 to 20 minutes before surgery

For status epilepticus:

• 100 μg/kg over at least 1 minute
• dose may be repeated every 5 to 10 minutes as needed
• must be diluted with an equal volume of saline (1:1 dilution)

For agitation / delirium:

• loading dose is 20 to 40 μg/kg IV bolus
• maintenance dosage is either:
  • 20 to 60 μg/kg IV bolus every 2 to 6 hours as needed, or infusion of 10 to 100 μg/kg/h

For alcohol withdrawal syndrome:

• dose according to symptoms
• 30 μg/kg oral, IM, or IV every 6 hours as needed for the first 24h
• 15 μg/kg oral, IM, or IV every 6 hours as needed for another 24h

For chemotherapy-associated nausea:

• 15 to 30 μg/kg oral or IV, every 6 hours

For psychogenic catatonia:

• 15 to 30 μg/kg orally, IM, or IV, administered daily
• initial dose can be repeated after 3 hours up to two additional times if the initial dose is ineffective
• continuing treatment can be titrated as necessary for symptoms up to a maximum of 120 μg/kg daily, with treatment continuing for up to 5 days.

Available forms

• 0.1 mg tablet

• 0.25 mg tablet

• 0.5 mg tablet

• 1 mg tablet

• 1 mg extended-release tablet

• 0.25 mg/mL oral solution

• 0.5 mg/mL injection solution

• 1 mg/mL injection solution

Pharmacokinetics

Route	Absorption Half-Life	Onset	Peak	Elimination Half-Life	Duration of action
IV	5 min	1-5 mins	Immediate	12-18 hrs	12-24 hrs
IM	15-20 mins	15-30 mins	60-90 mins
O	30 mins	20-30 mins	2 hrs		6-8 hrs

Oral bioavailability: 90%

Interactions

TODO