BSN Tracker

lorazepam

Brand: Ativan

⚠ BBW ISMP High Alert Beers Criteria Prototype: diazepam
Drug Class: benzodiazepine
Drug Family: benzodiazepine
Subclass: intermediate-acting benzodiazepine
Organ Systems: cns

Mechanism of Action

Positive allosteric modulator of GABA-A receptors; increases chloride channel opening frequency; no active metabolites, making it preferred in hepatic impairment and elderly patients.

GABA-A receptor (benzodiazepine binding site)

Indications

  • anxiety disorders
  • status epilepticus (first-line IV treatment)
  • procedural sedation/amnesia
  • alcohol withdrawal
  • acute agitation
  • chemotherapy-induced nausea (adjunct)

Contraindications

  • acute narrow-angle glaucoma
  • severe respiratory insufficiency
  • myasthenia gravis

Adverse Effects

Common

  • sedation
  • dizziness
  • weakness
  • anterograde amnesia
  • unsteadiness

Serious

  • respiratory depression
  • dependence and withdrawal seizures
  • propylene glycol toxicity (high-dose prolonged IV)

Pharmacokinetics (ADME)

Absorption Well absorbed orally and IM (90%)
Distribution Protein binding 91%; Vd 1.3 L/kg; crosses BBB
Metabolism Hepatic glucuronidation to inactive glucuronide — no active metabolites; safe in hepatic impairment (relative to other BZDs)
Excretion Renal as glucuronide
Half-life 10–20 hours
Onset IV: 1–5 minutes; IM: 15–30 minutes; oral: 30–60 minutes
Peak 2 hours (oral); 60–90 min (IM)
Duration 6–8 hours
Protein Binding 91%
Vd 1.3 L/kg

Drug Interactions

Drug / Agent Mechanism Severity
opioids additive CNS/respiratory depression major
clozapine additive sedation and risk of cardiovascular depression/arrest major
probenecid inhibits glucuronidation, prolonging lorazepam effect moderate

Nursing Considerations

  1. First-line IV benzodiazepine for status epilepticus: dose 0.1 mg/kg IV (max 4 mg per dose); may repeat once after 5 minutes; longer CNS duration than diazepam
  2. IV lorazepam is diluted 1:1 with NS, D5W, or sterile water immediately before administration; do not use pre-mixed solutions stored >24 hours
  3. Monitor respiratory rate, oxygen saturation, and level of consciousness during IV administration; resuscitation equipment must be available
  4. For alcohol withdrawal: use CIWA-Ar protocol to guide dosing; lorazepam preferred in patients with hepatic disease due to inactive metabolite profile

Clinical Pearls

  • Lorazepam is the preferred benzodiazepine in status epilepticus because its CNS duration of action (6–12 hours) is longer than diazepam's despite a similar half-life
  • The LOC (Lorazepam Over Conazepam) rule: Lorazepam is preferred in the elderly and hepatically impaired because it has no active metabolites and does not require Phase I hepatic metabolism

Safety Profile

Pregnancy use-with-caution
Lactation avoid
Renal Adjustment Not required
Hepatic Adjustment Not required
TDM Not required

Concordance Terms

Cross-referenced clinical concepts — click any term to see all content where it appears.

Acute Agitation Alcohol Withdrawal Anxiety Disorders Benzodiazepine Chemotherapy-induced Nausea (adjunct) Procedural Sedation/amnesia Status Epilepticus (first-line IV Treatment)
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