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:

  1. 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).
  2. “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.
  3. “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