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Due to the larger sample size from the two unpublished studies , carvedilol provided a better estimate of BP lowering effect than labetalol .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 .
Propranolol vs metoprolol vs labetalol: A comparative study in essential hypertension
Summary In a double blind , within patient investigation of twenty-four patients ( nineteen males and five females ) with a mean age of 46.3 years ( SD 10.9 years ) with mild to moderate essential hypertension a comparison between equipotent beta-blocking doses of propranolol , metoprolol and labetalol was carried out . Blood pressure and pulse rate were measured in lying , sitting and st and ing positions and before , during and after isometric and dynamic exercise . Peak expiratory flow was recorded before and during dynamic exercise . All the active treatments were better than placebo in reducing blood pressure and heart rate . Comparing the effects of treatment , labetalol lowered sitting diastolic pressure significantly more than propranolol and st and ing diastolic pressure than both propranolol and metoprolol . Metoprolol and propranolol were more effective in reducing heart rate .  Propranolol significantly reduced peak flow rate compared to labetalol . During the exercise , both isometric and dynamic , the heart rate and the blood pressure , both systolic and diastolic , of the treated patients were lower than those on placebo . There was little difference between the drugs in the influence on blood pressure , but metoprolol and propranolol were significantly more effective than labetalol in lowering the heart rate
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 .