Pharmacokinetic and pharmacological studies with clonidine in normal subjects

1. A highly specific and sensitive assay based on stable isotope dilution and mass fragmentography has been developed to measure clonidine in plasma. 2. Plasma half-lives of clonidine ranged from 6-9 to 9-4 h in five normotensive subjects. 3. Plasma clonidine concentration correlated with reduction in salivary flow and degree of sedation but not with change in blood pressure.