Plasma atropine concentrations via intravenous, endotracheal, and intraosseous administration.

To date, there have been limited studies on the pharmacokinetics of intravenous atropine and no pharmacokinetic studies on the endotracheal or intraosseous administration of atropine. This study examines the time to peak plasma concentration of atropine following intravenous, endotracheal, and intraosseous administration in anesthetized monkeys using a triple crossover design. Plasma atropine was assayed by a radioreceptor method. The time to peak plasma concentration of atropine was shortest with intravenous administration; and longest with endotracheal administration. The mean plasma concentration of atropine was significantly higher in intravenous administrations than in endotracheal administrations at 0.75 and 2 minutes; compared to that noted in intraosseous administrations, the concentration was significantly higher only at 0.75 minutes. The mean plasma concentration of atropine administered intraosseously was significantly higher than that of endotracheal administrations at 5 minutes and was greater than that of intravenous and endotracheal administrations for the samples collected from 5 to 30 minutes. The endotracheal and intraosseous routes provide alternatives to the intravenous administration of atropine when intravenous access is limited or not available.