[A new antihypertensive agent used in a clinical setting].

In a multicenter study with 54 patients with essential and renal hypertension (WHO I to III) the antihypertensive efficacy and safety of guanfacine were evaluated against clonidine in a double blind cross-over design. The treatment period for each drug lasted five weeks. There was a two week's wash-out period with placebo between the application of the respective preparations. During the first two weeks of treatment a daily dose of 3.3 mg guanfacine and 0.5 mg clonidine led to a significant fall in blood pressure from 187/103/138 mm Hg (s/d/m) to 152/86/113 mm Hg and from 186/101/136 mm Hg to 156/91/118 mm Hg respectively. During the following time blood pressure and dosage remained almost unchanged. In contrast to clonidine the guanfacine group showed a smaller fall in blood pressure in upright than in supine position. Both drugs showed a decrease of heart rate by approximately 4 beats per minute. Side effects such as dry mouth and tiredness were more pronounced under treatment with clonidine than with guanfacine (p less than or equal to 0,08). Guanfacine is well tolerated as a potential antihypertensive drug with relatively few side effects of mild nature.