Midazolam (Versed) 80/20 Clinical Summary

• Classes: Benzodiazepine sedative/hypnotic, anesthetic, anxiolytic, anticonvulsant.
• Mechanism: Enhances GABA-A receptors, increasing GABA affinity and opening chloride channels. This hyperpolarizes cell membranes, preventing excitation. Has twice the receptor affinity of diazepam.
• Pharmacokinetics: Metabolized by CYP3A4 to active, equipotent alpha-hydroxymidazolam. 97% protein-bound. Excreted via urine.
  • IV: Onset 1.5–5m, duration 30–45m. Tissue accumulation in long infusions delays awakening.
  • IM: Onset 5m, peak 15–30m.
  • PO: Onset 10–30m, duration 40–70m, ~36% bioavailability.
  • Intranasal (Nayzilam): Bioavailability 44–55%. Nasal burning lasts ~30s. ...