Effect Timings
Effect Timings
Onset of Effect
- <5 minutes following loading & infusion)
Peak of Effect
- Within 15 minutes following loading & infusion
Duration of Effect
- Given as infusion
Context Sensitive Half Time
- Favourably short, up to 4 hours after prolonged infusion
Absorption
Absorption
Oral Bioavailability
16%
Comments
- Extensive first-pass metabolism
- Primarily limited to intravenous use but can be given intranasally
Distribution
Distribution
Protein Binding
94%
(albumin and α1-glycoprotein)
(albumin and α1-glycoprotein)
Volume of Distribution (Vd)
1.31–2.46 L/kg
Comments
- Readily crosses the blood-brain and placenta barriers
Metabolism
Metabolism
Site
- Primarily metabolised in the liver
- Metabolised via glucuronidation and cytochrome 450 hydroxylation
Metabolites
- Metabolised to inactive metabolites
- Excreted renally (95%) and faecally (4%)
Elimination
Elimination
Distribution Half-Life
6 minutes
(rapid distribution phase)
(rapid distribution phase)
Terminal Half-Life
2 hours
Clearance
30-60 ml/min/kg