Transdermal administration of clonidine for treatment of high BP

The effectiveness of transdermally administered clonidine hydrochloride was evaluated in a multicenter study in 85 patients with mild essential hypertension. The drug was incorporated into small self-adhesive delivery systems (pliable skin patches, 3.5-sq-cm area) designed to continuously deliver 0.1 mg of clonidine hydrochloride per day. These devices were changed by the patients themselves at weekly intervals. Diastolic BP fell by at least 10% in 37 patients and was normalized (less than 90 mm Hg) in 54 patients (64%); 17 of these responding patients required only one skin patch, 27 required two, and the other ten responders required three. The antihypertensive action of the transdermal clonidine was sustained for the full three months of study. Side effects were similar to those during conventional oral treatment, but appeared to be milder.