Alfuzosin and the venous reflex response: studies in normal subjects.

1. Alfuzosin is a post-synaptic alpha-adrenoceptor antagonist with antihypertensive and peripheral vasodilator properties. 2. We measured the effect of alfuzosin, 5 mg, on sympathetically-mediated venoconstriction by changes in the venous reflex response (VRR) in a randomised, double-blind, placebo-controlled, crossover study in a group of 10 healthy volunteers. 3. There was a significant inhibition of the VRR after alfuzosin compared with placebo (P less than 0.001) which was present 1 h after the dose and still evident at 6 h. 4. Supine blood pressure was significantly lower (P less than 0.01) and supine heart rate was significantly higher (P less than 0.001) after alfuzosin compared with placebo. 5. Inhibition of the VRR by alfuzosin was observed to precede the development of reflex tachycardia.