Three clinical studies examined the effects of
guanfacine as monotherapy. Study 1 was a double-blind, randomized, parallel trial with a placebo control with 26 patients with mild
essential hypertension treated with 1-mg
guanfacine or matching placebo daily at bedtime for 8 weeks. Pretreatment and posttreatment determinations of plasma volume, plasma
aldosterone and blood pressure (BP) were made in all 26 patients. There were no significant differences between
guanfacine and placebo with regard to changes in plasma volume or plasma
aldosterone, but a significant decrease (p = 0.001) in both diastolic and mean BPs was seen with the active
drug. No side effects were reported. From this study, it was concluded that
guanfacine monotherapy is an effective and well-tolerated initial treatment for mild
essential hypertension with no effect on either plasma volume or plasma
aldosterone. Study 2 was a double-blind, randomized, parallel clinical study with placebo control with 42 patients with mild
essential hypertension treated with either
guanfacine (1 mg/day) or matching placebo at bedtime for 8 weeks. Pretreatment and posttreatment evaluations of serum
cholesterol,
triglycerides,
low density lipoproteins,
very low density lipoproteins and
high density lipoproteins revealed no significant differences between the treatment and the placebo groups. A statistically significant (p less than 0.0001) decrease in diastolic BP was seen in the
guanfacine group compared with those patients who received placebo.
Guanfacine monotherapy was again shown to be an effective initial treatment for mild
essential hypertension with no adverse influence on serum
lipids.(ABSTRACT TRUNCATED AT 250 WORDS)