The Safety and Efficacy of Quadruple Ultra-Low-Dose Combination (Quadpill) for Hypertension Treatment: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background and Objective Quadpill, a single pill containing a quadruple combination of quarter doses of four antihypertensive agents, has been investigated for hypertension treatment. This meta-analysis aims to evaluate the safety and efficacy of quadpill for hypertension management.Methods We conducted a systematic review and meta-analysis synthesizing randomized controlled trials evaluating quadpill versus monotherapy or placebo in patients with hypertension, which were retrieved by systematically searching PubMed, EMBASE, Web of Science, SCOPUS, and Cochrane through 17 February, 2023. Continuous and dichotomous outcomes were pooled using mean difference (MD) and risk ratio (RR) along with confidence interval (CI), using Revman Version 5.4 software. Our protocol has been published in PROSPERO with ID: CRD42023406527.Results Four randomized controlled trials with a total of 779 patients were included in our analysis. Quadpill was effective in controlling systolic blood pressure in the short term [4-6 weeks] (RR: - 13.00 with 95% CI [- 17.22, - 8.78], p = 0.00001) and in the long term [12 weeks] (RR: - 6.18 with 95% CI [- 9.35, - 3.01], p = 0.0001). Quadpill was also effective in controlling automated diastolic blood pressure in the short term [4-6 weeks] (MD: - 8.15 with 95% CI [- 9.42, - 6.89], p = 0.00001) and in the long term [12 weeks] (MD: - 6.35 with 95% CI [- 10.37, - 2.33], p = 0.002). Moreover, patients in the quadpill group significantly achieved target blood pressure <140/90 (RR: 1.77 with 95% CI [1.26, 2.51], p = 0.001) compared with the control group.Conclusions The quadruple ultra-low-dose combination of antihypertensive drugs (quadpill) was effective and safe for hypertension treatment. However, further large-scale, multicenter, randomized controlled trials are still warranted before endorsement in clinical practice.