Lorazepam (Temelor)

Mechanism of action

Benzodiazepine and anticonvulsant.

Acts on benzodiazepine receptor via GABA-A receptor and enhances its inhibitory effect through increased permeability for chloride ions.

Dose-related effect. Causes sedation, anxiolysis, anterograde amnesia, muscle relaxation and has an anticonvulsant effect. At higher doses causes cardiorespiratory depression.

Indications and dose



Respiratory depression


Drowsiness; excess sedation

Paradoxical agitation (more common in elderly)

Cardiovascular depression


Onset of action: Intravenous: 10 minutes; Intramuscular: 20-30 minutes

Duration of action: 6-8 hours

Bioavailability: Oral: 90%

Distribution: 90% protein bound

Metabolism: Hepatic

Half-life of elimination: 14 hours

Excretion: Urine

Reversal agent

Flumazenil - benzodiazepine antagonist

Directions for administration

Dilute in water for injection or 0.9% sodium chloride

Medicinal forms

Tablet - 0.5mg, 1mg and 2.5mg

Solution for injection - 1 vial = 2mg in 1 ml or 4mg in 1 ml.

Oral solution


1) https://bnf.nice.org.uk/drugs/lorazepam/

2) https://www.uptodate.com/contents/lorazepam-drug-information?search=lorazepam&source=panel_search_result&selectedTitle=1~148&usage_type=panel&kp_tab=drug_general&display_rank=1#F189903