Value of low dose combination treatment with blood pressure lowering drugs: analysis of 354 randomised trials

To determine the average reduction in blood pressure, prevalence of adverse effects, and reduction in risk of stroke and ischaemic heart disease events produced by the five main categories of blood pressure lowering drugs according to dose, singly and in combination.

Meta-analysis of 354 randomised double blind placebo controlled trials of thiazides, beta blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin II receptor antagonists, and calcium channel blockers in fixed dose. SUBJECTS: 40,000 treated patients and 16,000 patients given placebo. MAIN OUTCOME MEASURES: Placebo adjusted reductions in systolic and diastolic blood pressure and prevalence of adverse effects, according to dose expressed as a multiple of the standard (recommended) doses of the drugs.