Effects of clonidine on intravenous sedation with midazolam

The effect of clonidine, an alpha 2-adrenoceptor agonist, on intravenous (IV) sedation with midazolam was studied. Subjects were eight healthy adults; IV sedation was performed twice on each subject. In the control (CO) group, midazolam alone was administered. In the clonidine (CL) group, the subjects were given about 5 micrograms/kg of clonidine orally 2 hr before the initiation of sedation with midazolam. The following parameters were determined: dose of midazolam, changes in vital signs, recovery time, amnesia, and side effects. The average sedating dose of midazolam was 0.078 and 0.043 mg/kg in the CO and CL groups, respectively. Recovery times determined by stabilometry were 150 and 120 min in the CO and CL groups, respectively. Based on these results, the combined use of clonidine can reduce the dose of midazolam and shorten the recovery time. It is suggested that clonidine may be useful in IV sedation with midazolam.