Lorazepam (Psychiatric/Acute Use)

How it works

It enhances the inhibitory action of gamma-aminobutyric acid at the GABA-A receptor, increasing chloride conductance to produce anxiolytic, sedative and anticonvulsant effects.

Prescribing in practice

• Respiratory and central nervous system depression can be profound, especially with parenteral use or alongside opioids and other depressants, so monitor airway, breathing and sedation and have flumazenil and resuscitation facilities available during rapid tranquillisation.
• Use the lowest effective dose for the shortest time because of dependence and withdrawal risk, and avoid abrupt cessation after regular use.
• Caution in the elderly, respiratory disease, hepatic impairment and where paradoxical agitation may occur; injectable forms require appropriate dilution and monitoring.

Monitoring

During acute use monitor conscious level, respiratory rate, oxygen saturation and blood pressure, and on continued use review for tolerance and dependence.

Counselling the patient

• This medicine causes marked drowsiness; do not drive or operate machinery until fully recovered.
• Avoid alcohol and other sedatives, which dangerously increase drowsiness and breathing problems.
• Use is intended to be short term to avoid dependence.

Evidence & guidelines

NICE guidance on violence and aggression supports lorazepam as an option for rapid tranquillisation, with close monitoring of vital signs.