Transdermal clonidine for hypertensive patients.

Seventeen moderately hypertensive patients, whose blood pressure was previously controlled with hydrochlorothiazide and oral clonidine (blood pressure 129 +/- 8/85 +/- 5 mmHg during therapy), were treated with a transdermal system involving application of one or more clonidine-containing patches (3 mg per patch) to the skin once a week. The patients continued to take 50 mg of oral hydrochlorothiazide daily. By four to eight weeks, 15 of 17 patients using the transdermal system had achieved baseline blood pressure levels (130 +/- 10/84 +/- 6 mmHg, NS). During the maintenance phase of transdermal therapy, plasma clonidine levels measured four hours (0.78 +/- 0.43 ng/ml), four days (0.89 +/- 0.48 ng/ml), and seven days (0.78 +/- 0.41 ng/ml) after patch application did not differ significantly from one another or from trough plasma clonidine levels (0.86 +/- 0.54 ng/ml) measured during oral clonidine therapy. The results suggest that, in moderately hypertensive patients, blood pressure can be controlled with a once-weekly application of clonidine-containing skin patches as effectively as with oral clonidine.