Intervention Review

Blood pressure lowering efficacy of beta-blockers as second-line therapy for primary hypertension

  1. Jenny MH Chen1,*,
  2. Balraj S Heran2,
  3. Marco I Perez1,
  4. James M Wright1

Editorial Group: Cochrane Hypertension Group

Published Online: 20 JAN 2010

Assessed as up-to-date: 10 NOV 2009

DOI: 10.1002/14651858.CD007185.pub2


How to Cite

Chen JMH, Heran BS, Perez MI, Wright JM. Blood pressure lowering efficacy of beta-blockers as second-line therapy for primary hypertension. Cochrane Database of Systematic Reviews 2010, Issue 1. Art. No.: CD007185. DOI: 10.1002/14651858.CD007185.pub2.

Author Information

  1. 1

    University of British Columbia, Department of Anesthesiology, Pharmacology and Therapeutics, Vancouver, BC, Canada

  2. 2

    Peninsula College of Medicine & Dentistry, University of Exeter, Peninsula Technology Assessment Group (PenTAG), Exeter, Devon, UK

*Jenny MH Chen, Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, 2176 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada. jenny.chen@ti.ubc.ca. koko_jesse@hotmail.com.

Publication History

  1. Publication Status: New
  2. Published Online: 20 JAN 2010

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Abstract

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

Background

Beta-blockers are one of the more commonly prescribed classes of anti-hypertensive drugs, both as first-line and second-line.

Objectives

To quantify the effect on systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate and withdrawals due to adverse effects of beta-blocker therapy when given as a second-line drug in adult patients with primary hypertension.

Search methods

CENTRAL (The Cochrane Library 2009, Issue 2), MEDLINE (1966-Aug 2009), EMBASE (1988-Aug 2009) and bibliographic citations of articles and reviews were searched.

Selection criteria

Double-blind, randomized controlled trials comparing a beta-blocker in combination with a drug from another class of anti-hypertensive drugs compared with that drug alone for a duration of 3 to 12 weeks in patients with primary hypertension were included.

Data collection and analysis

Two reviewers independently extracted the data and assessed trial quality of each included study.

Main results

20 double-blind RCTs evaluated the BP lowering efficacy of beta-blockers as second-line drug in 3744 hypertensive patients (baseline BP of 158/102 mmHg; mean duration of 7 weeks). The BP reduction from adding a beta-blocker as the second drug was estimated by comparing the difference in BP reduction between the combination and monotherapy groups. A reduction in BP was seen with adding a beta-blocker to thiazide diuretics or calcium channel blockers at doses as low as 0.25 times the manufacturer's recommended starting dose. The BP lowering efficacy of beta-blockers as a second drug was 6/4 mmHg at 1 times the starting dose and 8/6 mmHg at 2 times the starting dose. Beta-blockers reduced heart rate by 10 beats/min at 1 to 2 times the starting dose. Beta-blockers did not statistically significantly increase withdrawals due to adverse effects but this was likely due to the lack of reporting of this outcome in 35% of the included RCTs.

Authors' conclusions

Addition of a beta-blocker to diuretics or calcium-channel blockers reduces BP by 6/4mmHg at 1 times the starting dose and by 8/6 mmHg at 2 times the starting dose. When the blood pressure lowering effect of beta-blockers from this review was compared to that of thiazide diuretics from our previous review (Chen 2009), second-line beta-blockers reduce systolic BP to the same extent as second-line thiazide diuretics, but reduce diastolic BP to a greater degree. The different effect on diastolic BP means that beta-blockers have little or no effect on pulse pressure whereas thiazides cause a significant dose-related decrease in pulse pressure. This difference in the pattern of BP lowering with beta-blockers as compared to thiazides might be the explanation for the fact that beta-blockers appear to be less effective at reducing adverse cardiovascular outcomes than thiazide diuretics, particularly in older individuals.

 

Plain language summary

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

Beta-blockers lower blood pressure when given as a second drug

Beta-blockers are commonly used in the treatment for high blood pressure (BP). In this review, we asked how much do beta-blockers reduce BP when used as the second drug to treat hypertension. Twenty trials lasting an average of 7 weeks were found in the world scientific literature to answer this question. The data showed that the addition of a beta-blocker to thiazide diuretics or calcium channel blockers reduced BP by 8/6 mmHg when given at doses 2 times the recommended starting dose. When we compared these results with our previous review of the blood pressure lowering effect of thiazide diuretics as second line drug, we found that beta-blockers have a different pattern of BP lowering. This different pattern of effect on blood pressure might explain why first-line beta-blockers appear to be less effective at reducing adverse cardiovascular outcomes than first-line thiazide diuretics, particularly in older individuals.

 

摘要

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

背景

乙型阻斷劑作為本態性高血壓第二線治療的效果

乙型阻斷劑是最常被處方來治療高血壓的藥物之一,可以用在第一線也可以當作第二線的高血壓用藥。

目標

量化乙型阻斷劑作為成年人本態性高血壓第二線治療的各種效果,包括收縮壓、 (SBP) 、舒張壓 (DBP) 、心律和因為治療產生的副作用而停藥的比例。

搜尋策略

我們搜尋了CENTRAL (The Cochrane Library 2009, Issue 2), MEDLINE (1966Aug 2009), EMBASE (1988Aug 2009) 和bibliographic citations of articles and reviews。

選擇標準

納入分析的需為雙盲隨機對照試驗,且為比較使用乙型阻斷劑合併另一類藥物時和單獨使用此類藥物時治療本態性高血壓的效果,時間為3至12週。

資料收集與分析

由兩位作者獨立擷取資料並評估納入分析的臨床試驗的品質。

主要結論

總共有20個雙盲隨機對照試驗評估乙型阻斷劑作為成年人本態性高血壓第二線治療的降壓效果,共有3744位高血壓病患 (試驗開始前之平均血壓為150/102毫米汞柱,平均試驗時間為七週) 。評估加上乙型阻斷劑作為第二線治療的降壓效果的方式為比較使用乙型阻斷劑合併另一類藥物時和單獨使用此類藥物時血壓的差異。當thiazide類利尿劑或是鈣離子阻斷劑加上生產商建議的起始劑量的25% 乙型阻斷劑時就開始有血壓下降的效果。乙型阻斷劑作為第二線治療的降壓效果在建議的起始劑量的1倍時為6/4毫米汞柱,2倍時為8/6毫米汞柱。乙型阻斷劑在建議的起始劑量的1到2倍時減少心跳每分鐘10下。因為藥物不良反應而停用乙型阻斷劑在統計學上並無有意義的增加,但這可能是因為其中35% 的隨機對照試驗都沒有這方面的評估報告。

作者結論

使用利尿劑或是鈣離子阻斷劑後再加上乙型阻斷劑,其降低血壓的效果在起始劑量的1倍時為6/4毫米汞柱,2倍時為8/6毫米汞柱。乙型阻斷劑作為第二線治療的降壓效果拿來跟我們之前對thiazide類利尿劑作為第二線治療的降壓效果所做的系統性回顧 (Chen 2009) 結果來做比較時,可以發現兩者對於收縮壓的下降程度是差不多的,但乙型阻斷劑可降低舒張壓的程度更多。這樣的差異代表乙型阻斷劑對於脈壓的影響是很少甚至是沒有的,而thiazide類利尿劑則可減少脈壓,且隨著劑量越大,減少的幅度越多。兩者降低血壓形式的不同可以解釋為何乙型阻斷劑對於減少不良心血管事件的效果較差,尤其是在年紀較大的族群。

翻譯人

本摘要由澄清醫院沈坤泰翻譯。

此翻譯計畫由臺灣國家衛生研究院 (National Health Research Institutes, Taiwan) 統籌。

總結

乙型阻斷劑作為高血壓第二線用藥時可以降低血壓。乙型阻斷劑常被用來治療高血壓。在這個系統性回顧中,我們想要知道乙型阻斷劑作為高血壓第二線用藥時可以降低多少血壓。我們從全球的文獻中總共找到了20個隨機對照試驗,平均試驗時間為七週,來回答這個問題。資料分析顯示,使用利尿劑或是鈣離子阻斷劑後再加上乙型阻斷劑,其降低血壓的效果在起始劑量的2倍時為8/6毫米汞柱。將此結果跟之前對thiazide類利尿劑作為第二線治療的降壓效果所做的系統性回顧結果來做比較時,我們發現乙型阻斷劑對血壓降低的形式不同。這樣的差異或許可以解釋當乙型阻斷劑作為第一線高血壓治療藥物時,比thiazide類利尿劑作為第一線高血壓治療藥物時,對於減少不良心血管事件的效果較差,尤其是在年紀較大的族群。