OBJECTIVE: Although alpha-blockers are effective in lowering blood pressure, they may increase heart rate, an unwanted effect that could negatively affect outcome. However, the alpha-blocker urapidil might not increase heart rate due to its additional effect on 5-HT1A receptors. Therefore, we compared the effects of urapidil on heart rate with those of another alpha-blocker, doxazosin. METHODS: We performed a randomised, double-blind, placebo-controlled, cross-over study in 12 healthy males who received single oral doses of 60 mgurapidil, 4 mg doxazosin and placebo. Four hours following drug intake, heart rate and blood pressure were measured at rest and during exercise. RESULTS: Both doxazosin and urapidil decreased blood pressure to the same extent. Compared to placebo, resting heart rate was significantly increased by doxazosin (+25%, P < 0.05) but not by urapidil (+12%, n.s.). Resting heart rate with doxazosin was significantly higher than with urapidil (P < 0.05). Similarly, the rate pressure product (RPP) at rest was increased by doxazosin (+17%, P < 0.05) but not by urapidil (+6%, n.s.). CONCLUSIONS: We conclude that the increase in heart rate caused by urapidil is less pronounced than that with doxazosin, a property that might favour urapidil in the treatment of arterial hypertension. In addition, only doxazosin (but not urapidil) increased the RPP at rest, a finding that might be helpful to explain why this drug was never shown to improve outcome in the treatment of arterial hypertension.
RCT Entities:
OBJECTIVE: Although alpha-blockers are effective in lowering blood pressure, they may increase heart rate, an unwanted effect that could negatively affect outcome. However, the alpha-blocker urapidil might not increase heart rate due to its additional effect on 5-HT1A receptors. Therefore, we compared the effects of urapidil on heart rate with those of another alpha-blocker, doxazosin. METHODS: We performed a randomised, double-blind, placebo-controlled, cross-over study in 12 healthy males who received single oral doses of 60 mg urapidil, 4 mg doxazosin and placebo. Four hours following drug intake, heart rate and blood pressure were measured at rest and during exercise. RESULTS: Both doxazosin and urapidil decreased blood pressure to the same extent. Compared to placebo, resting heart rate was significantly increased by doxazosin (+25%, P < 0.05) but not by urapidil (+12%, n.s.). Resting heart rate with doxazosin was significantly higher than with urapidil (P < 0.05). Similarly, the rate pressure product (RPP) at rest was increased by doxazosin (+17%, P < 0.05) but not by urapidil (+6%, n.s.). CONCLUSIONS: We conclude that the increase in heart rate caused by urapidil is less pronounced than that with doxazosin, a property that might favour urapidil in the treatment of arterial hypertension. In addition, only doxazosin (but not urapidil) increased the RPP at rest, a finding that might be helpful to explain why this drug was never shown to improve outcome in the treatment of arterial hypertension.
Authors: Paolo Palatini; Lutgarde Thijs; Jan A Staessen; Robert H Fagard; Christopher J Bulpitt; Denis L Clement; Peter W de Leeuw; Matti Jaaskivi; Gastone Leonetti; Choudomir Nachev; Eoin T O'Brien; Gianfranco Parati; José L Rodicio; Elisabetta Roman; Cinzia Sarti; Jaakko Tuomilehto Journal: Arch Intern Med Date: 2002-11-11
Authors: Xavier Jouven; Jean-Philippe Empana; Peter J Schwartz; Michel Desnos; Dominique Courbon; Pierre Ducimetière Journal: N Engl J Med Date: 2005-05-12 Impact factor: 91.245
Authors: Aram V Chobanian; George L Bakris; Henry R Black; William C Cushman; Lee A Green; Joseph L Izzo; Daniel W Jones; Barry J Materson; Suzanne Oparil; Jackson T Wright; Edward J Roccella Journal: Hypertension Date: 2003-12-01 Impact factor: 10.190