Lorazepam

Short/Intermediate-acting·Neurology - Sedatives & Hypnotics

Acute agitation, status epilepticus, short-term anxiety, alcohol withdrawal in hepatic impairment

Authority requiredPBSBENZOAtivan1 mg tablet+2

Max Dose

4 mg/day

Half-life

10-20 h

Hepatic Safe

L.O.T. DRUG

Dependence

HIGH RISK

Rapid Summary

Overview

Intermediate-acting benzodiazepine. Does not require hepatic phase 1 metabolism, making it highly predictable and incredibly safe for the elderly and those with liver failure.

Maximum Dose

Max 4 mg/day (Usually given in 0.5 - 1 mg doses).

Clinical Focus

The drug of choice for acute seizures or severe agitation in patients with end-stage liver cirrhosis.

Bottom Line

Lorazepam is the preferred benzodiazepine in hepatic impairment and status epilepticus (no active metabolites), but causes significant sedation and respiratory depression, and is highly dependency-forming.

Formulation & Access

Brand Names

Ativan

Oral Routes

Tablets (1 mg, 2.5 mg). Can be dissolved sublingually.

Parenteral

Ampoules for IV / IM use. (Unlike Diazepam, IM absorption is excellent and predictable).

Prescribing & PBS

Authority Required (PBS).

Indications & Use

Primary

PBSTGA

Acute agitation, status epilepticus, short-term anxiety, alcohol withdrawal in hepatic impairment.

Clinical Place

Highly versatile. Binds tightly to the receptor, providing longer clinical effect than its half-life suggests.

Quick reference

Class & Role

Short/Intermediate-acting — Intermediate-acting benzodiazepine.

Route / Formulation

Tablets (1 mg, 2.5 mg). Can be dissolved sublingually. (Ativan)

Usual Dose & Max

PO or SL 0.5 - 1 mg PRN. Max 4 mg/day.

Key Indication Doses

Acute Anxiety / Agitation: PO or SL 0.5 - 1 mg PRN. Max 4 mg/day. Status Epilepticus: IV 4 mg slow push (2 mg/min). Alcohol Withdrawal (Hepatic Failure): PO 1-2 mg q2h PRN (replaces diazepam).

Best Uses

Avoid / Cautions

Severe respiratory failure, Myasthenia Gravis.

Key Risks

Neurological: Sedation, amnesia, ataxia, dependence, withdrawal seizures. Respiratory: Respiratory depression when combined with opioids or pushed too rapidly IV.

Key Interactions

Opioids, Alcohol, Barbiturates (fatal respiratory depression).

Monitoring

Monitor SpO2 and RR during IV use. High falls risk on the ward. No specific routine laboratory tests required.

Clinical Pearl

While not officially marked as sublingual, the 1mg and 2.5mg Ativan tablets dissolve rapidly under the tongue. This bypasses the gut and provides rapid relief for acute panic or agitation when an IV line isn't available.

Access

Authority requiredAtivan1 mg tablet

Brand: Ativan
PBS status: Authority required
Formulation: Tablets (1 mg, 2