Effects of clonidine and yohimbine on the pupillary light reflex and carbachol-evoked sweating in healthy volunteers.

The effects of single doses of clonidine hydrochloride (200 micrograms), yohimbine hydrochloride (22 mg), a combination of the two treatments, and placebo, on some autonomic functions were studied in healthy volunteers using a double-blind crossover design. Clonidine prolonged the recovery time of the light reflex, lowered systolic blood pressure and reduced subjectively rated alertness; these effects were reversed by yohimbine. Responsiveness of sweat glands to carbachol was not affected by the treatments.

RCT Entities:   Population Interventions Outcomes