Midazolam (Surgical — Anxiolysis/Sedation)

How it works

It potentiates the inhibitory neurotransmitter GABA at the GABA-A receptor, producing sedation, anxiolysis, anterograde amnesia and muscle relaxation.

Prescribing in practice

• Titrate slowly to effect with full resuscitation facilities and continuous monitoring, because midazolam causes dose-dependent respiratory depression and hypotension — risk is markedly increased by concomitant opioids and in the elderly, who need substantially reduced doses.
• Have the reversal agent flumazenil immediately available, and reduce dose in hepatic impairment, debilitated patients and where other CNS depressants are used.
• Allow adequate time for each increment to take effect before redosing, as delayed onset can lead to inadvertent oversedation.

Monitoring

Monitor respiratory rate, oxygen saturation, blood pressure and conscious/sedation level continuously throughout and during recovery.

Counselling the patient

• Explain it is a sedative given by injection to relax you, and that you may not remember parts of the procedure.
• Do not drive, operate machinery, drink alcohol or make important decisions for the rest of the day after sedation, and arrange for someone to accompany you home.

Evidence & guidelines

Midazolam is a standard agent for procedural sedation and anaesthetic premedication; UK safe-sedation guidance and the SPC stress titration, monitoring, dose reduction in the elderly and flumazenil availability.