Carvedilol , within the recommended dose range , did not show a significant dose response effect for SBP or DBP .
Carvedilol had little or no effect on pulse pressure ( -1 mm Hg ) and did not change BP variability .
Due to the larger sample size from the two unpublished studies , carvedilol provided a better estimate of BP lowering effect than labetalol .
Doses higher than the recommended starting dose did not provide additional BP reduction .
Higher doses of dual receptor blockers caused more bradycardia than lower doses .
Based on indirect comparison with other classes of drugs , the blood pressure lowering effect of dual alpha- and beta-receptor blockers is less than non-selective , beta1 selective and partial agonist beta blockers , as well as thiazides and drugs inhibiting the renin angiotensin system .
Dual blockers also had little or no effect on reducing pulse pressure , which is similar to the other beta-blocker classes , but less than the average reduction of pulse pressure seen with thiazides and drugs inhibiting the renin angiotensin system .
Patients taking dual receptor blockers  were not more likely to withdraw from the study compared to patients taking placebo
BACKGROUND Drugs with combined alpha and beta blocking activity are commonly prescribed to treat hypertension .
However , the blood pressure ( BP ) lowering efficacy of this class of beta blockers has not been systematic ally review ed and quantified .
OBJECTIVES To quantify the dose-related effects of various types of dual alpha and beta adrenergic receptor blockers ( dual receptor blockers ) on systolic and diastolic blood pressure versus placebo in patients with primary hypertension .
Combined alpha- and beta-adrenoceptor blockade with labetalol in hypertension.
The antihypertensive effect of labetalol , a new alpha- and beta-adrenoceptor inhibiting agent , was studied in 20 patients in a double-blind crossover trial . A dose of 300 mg daily reduced blood pressure only moderately in the supine position , though in the sitting and st and ing positions the effect was more pronounced . A dose of 600 mg daily produced statistically significant and clinical ly relevant reductions in blood pressure in all positions studied . The effect on heart rate was small and of significance only in reducing the heart rate increment due to a change in posture . Side effects were mild : only one patient complained of postural dizziness with the higher dose . We conclude that labetalol is useful in the treatment of mild and moderately severe hypertension
Carvedilol , within the recommended dose range , did not show a significant dose response effect for SBP or DBP .
Carvedilol had little or no effect on pulse pressure ( -1 mm Hg ) and did not change BP variability .
Due to the larger sample size from the two unpublished studies , carvedilol provided a better estimate of BP lowering effect than labetalol .
Doses higher than the recommended starting dose did not provide additional BP reduction .
Higher doses of dual receptor blockers caused more bradycardia than lower doses .
Based on indirect comparison with other classes of drugs , the blood pressure lowering effect of dual alpha- and beta-receptor blockers is less than non-selective , beta1 selective and partial agonist beta blockers , as well as thiazides and drugs inhibiting the renin angiotensin system .
Dual blockers also had little or no effect on reducing pulse pressure , which is similar to the other beta-blocker classes , but less than the average reduction of pulse pressure seen with thiazides and drugs inhibiting the renin angiotensin system .
Patients taking dual receptor blockers  were not more likely to withdraw from the study compared to patients taking placebo
BACKGROUND Drugs with combined alpha and beta blocking activity are commonly prescribed to treat hypertension .
However , the blood pressure ( BP ) lowering efficacy of this class of beta blockers has not been systematic ally review ed and quantified .
OBJECTIVES To quantify the dose-related effects of various types of dual alpha and beta adrenergic receptor blockers ( dual receptor blockers ) on systolic and diastolic blood pressure versus placebo in patients with primary hypertension .