Low-dose drug combinations that incorporate between three and four blood pressure (BP)-lowering medications appear to be well tolerated and effective for the initial or early management of hypertension, according to the results of a systematic review and meta-analysis.
Researchers searched multiple online databases for relevant studies and identified seven trials that met the inclusion criteria. Four trials involved triple-component low-dose combinations, while three trials involved quadruple-component low-dose combinations. The total population comprised 1,918 participants (mean age 59 years, 38 percent women) with hypertension.
The primary endpoint was mean reduction in systolic BP (SBP) between combination therapy and monotherapy, usual care, or placebo. Other outcomes of interest included the proportion of patients achieving BP <140/90 mm Hg, rates of adverse effects, and treatment withdrawal.
Pooled data showed that at 4–12 weeks follow-up, the mean reduction in SBP was significantly greater with combination therapy than with monotherapy or usual care (mean reduction, 7.4 mm Hg, 95 percent confidence interval [CI], 4.3–10.5) and placebo (mean reduction, 18.0 mm Hg, 95 percent CI, 15.1–20.8).
Additionally, more participants on combination therapy achieved BP <140/90 mm Hg at 4–12 weeks as compared to those on monotherapy or usual care (66 percent vs 46 percent; risk ratio [RR], 1.40, 95 percent CI, 1.27–1.52) and those on placebo (54 percent vs 18 percent; RR, 3.03, 95 percent CI, 1.93–4.77).
No significant heterogeneity was found across trials enrolling individuals with and without baseline BP-lowering therapy. Data from two trials showed that combination therapy performed consistently better than monotherapy or usual care at 6 to 12 months.
In terms of safety, the combination therapy was associated with more dizziness compared with monotherapy or usual care (14 percent vs 11 percent; RR, 1.28, 95 percent CI, 1.00–1.63). Nevertheless, none of the participants on combination therapy discontinued treatment.