ClassIndications
Administration/Absorption- Intravenous midazolam is indicated for procedural sedation (often in combination with an opioid, such as fentanyl)
- Oral
- poorly absorbed orally with only 50 percent of the drug reaching the
bloodstream
Dosage
DistributionMechanism- Benzodiazepines bind at the interface of the α and γ subunits on the GABAA receptor
- Requires that alpha subunits contain a histidine amino acid residue, (i.e., α1, α2, α3 and α5 containing GABAA receptors)
- Benzodiazepines show no affinity for GABAA receptors containing α4 and α6 subunits with an arginine instead of a histidine residue.[118]
- Benzodiazepine ligand locks the benzodiazepine receptor into a conformation in which it has a greater affinity for the GABA neurotransmitter
- This increases the frequency of the opening of the associated chloride ion channel and hyperpolarizes
the membrane of the associated neuron
- The inhibitory effect of the
available GABA is potentiated, leading to sedatory and anxiolytic
effects.
Excretion- short-acting benzodiazepine in adults with an elimination half-life of
one to four hours
- Midazolam is metabolised into an active metabolite
alpha1-hydroxymidazolam
- However, the active metabolite of midazolam is minor and contributes to
only 10 percent of biological activity of midazolam.
- Metabolised by cytochrome P450 (CYP) enzymes and by glucuronide conjugation
Side effectsInteractions
Contraindications
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