Dose-titration study of alfuzosin, a new alpha 1-adrenoceptor blocker, in essential hypertension.

An open, dose-titration study of alfuzosin, a new selective post-synaptic alpha 1-adrenoceptor antagonist with additional direct vasodilator properties has been performed. After a 3-week run-in placebo period, 12 patients with essential hypertension received alfuzosin 5 mg oral b.d., and then the dose was doubled every week, up to a maximum of 20 mg q.i.d. if the supine diastolic blood pressure was greater than 90 mm Hg. The study lasted for 4 weeks. Supine blood pressure (SBP) decreased from 160/102 (Day 0) to 148/89 mm Hg and upright blood pressure (UBP) from 151/102 (Day 0) to 137/84 mm Hg. Alfuzosin did not cause any significant change in supine or upright heart rate. In addition, after the first dose of alfuzosin, supine and upright blood pressure and heart rate (SHR and UHR) were measured every 30 min for 5 h. The fall in blood pressure was significant after 90 min and it lasted up to the 5th hour; the maximum effect was observed after 3 h: SBP decreased from 159/103 (time 0) to 137/84 mm Hg and UBP from 150/102 (time 0) to 123/79 mm Hg. SHR was increased from 72 (time 0) to 81 beats/min at the 5th hour and UHR from 87 to 101 beats/min at the 4th hour. A weak but significant correlation was observed between the hypotensive effect 12 h after drug intake and the plasma concentration of the drug at that time. A 10% decrease in supine diastolic blood pressure was found at a drug plasma concentration higher than 7 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)