Midazolam

• Used for:

  • Reducing anxiety (anxiolytic) and supplementing the primary sedative agent

  • GA goals met: Sedation/hypnosis, Anterograde amnesia

• Mechanism: 

  • Benzodiazepine drug class: Inhibits CNS activity by increasing the inhibitory effects of the GABA-a receptor.

• Physiological effects:

  • Mildly decreases in BP: Induces systemic vasodilation by blocking sympathetic tone, and decreases cardiac output.

  • Stable HR: Midazolam blocks the baroreceptor reflex. 

  • Mild respiratory effects. In higher doses, causes rapid, shallow breathing (increased RR and decreased TV). 

• Adverse effects:

  • Acute delirium

  • Postoperative cognitive dysfunction in older patients

Benzodiazepine Overdose Presentation:

• CNS depression (drowsiness, slurred speech)

• Rapid, shallow breathing (reduced TV, increased RR)

• Co-ingestion with opioids or ethanol can be fatal due to the resulting respiratory depression

• Antidote: Flumazenil