Background: The alpha2 agonist clonidine has become a popular drug for premedication in children. Effects and pharmacokinetics after oral, rectal, and intravenous administration are well known. The aim of this study was to investigate the absorption pharmacokinetics of clonidine nasal drops in children.
Methods: Thirteen ASA I pediatric patients received after induction of anesthesia 4 mcg x kg(-1) of clonidine by the nasal route. Blood samples were taken during a 12-h period and plasma levels of clonidine were analyzed by liquid chromatography-mass spectrometry. Data were calculated by a computer-aided curve-fitting program.
Results: Plasma pharmacokinetics following administration of clonidine nasal drops showed a considerable interindividual variability and absorption was delayed and limited. A total of 95% confidence intervals for maximum plasma concentration and time to achieve maximum plasma concentration were 0.4-0.6 ng x ml(-1) and 1.4-3.0 h, respectively.
Conclusions: Clonidine nasal drops are erratically absorbed from the nasal mucosa and, thus, this mode of drug administration is not recommended for premedication purposes.