Does intranasal dexmedetomidine provide adequate plasma concentrations for sedation in children: a pharmacokinetic study.
Intranasal dexmedetomidine (DMT) has been used for sedation in children around the world (including in our institution) for some years now – interestingly in the absence of any pharmacokinetic data.
This paper from Cincinnati Children’s Hospital Medical Centre studied a small group (n=18) of children to redress this issue. The children were all undergoing cardiac surgery so arterial sampling was part of their standard care. They were randomly allocated to receive intranasal DMT 1mcg/kg or intranasal DMT 2mcg/kg or intravenous DMT 1 mcg/kg (to allow the bioavailability to be calculated).
Take home messages:
- “it does get in” The bioavailability was 84% – i.e it gets absorbed well from the nasal mucosa into the bloodstream (gastrointestinal degradation and hepatic first pass metabolism are, of course avoided).
- “the more you give, the quicker it works” mean plasma concentrations reached the low end of level needed for sedation after 20 mins with the 1mcg/kg intranasal dose and after 10 mins with the 2mcg/kg dose.
- “it lasts some time” peak plasma levels were reached 47mins after administration of both intranasal doses.
Warning: this paper contains mathematical formulae – all of which were ignored by me.
Reviewed by: Dr Chris Smit