Efficacy and Safety of Chinese Herbal Medicine Compared With Losartan for Mild Essential Hypertension: A Randomized, Multicenter, Double-Blind, Noninferiority Trial

Abstract

Background: Hypertension is one of the most challenging public health problems worldwide. Previous studies suggested that the Songling Xuemaikang capsule (SXC)—a Chinese herbal formula—was effective for essential hypertension. However, the efficacy of SXC monotherapy for hypertension remains unclear. We aimed to compare the blood pressure (BP)–lowering efficacy and safety of SXC versus losartan in patients with essential hypertension. Methods: In this multicenter, randomized, double-blind, noninferiority trial in China, patients 18 to 65 years of age with mild essential hypertension were randomly allocated to receive either SXC or losartan for 8 weeks. The primary outcome was the change in sitting diastolic BP from baseline to 8 weeks, with a predefined noninferiority margin of −2.5 mm Hg. Results: Of the 755 patients who entered a 2-week run-in period, 628 patients (327 women and 301 men; mean [SD] age, 52.6 [9.2] years) were randomly assigned to the SXC (n=314) or losartan (n=314) group. The primary analysis based on the intention-to-treat principle showed that the change in diastolic BP from baseline to 8 weeks was similar between the SXC and losartan groups (−7.9 [8.0] versus −8.1 [7.9]). The lower boundary of 95% CI (mean difference, −0.24 [95% CI, −1.51 to 1.03]) was above the margin of −2.5 mm Hg, showing noninferiority. Results were consistent with per-protocol analysis. SXC produced greater improvements in total hypertension symptom score (−5.7 [4.2] versus −5.0 [4.0]; P =0.020) and total cholesterol (−0.1 [1.0] versus 0.1 [1.2]; P =0.025). There were no differences between groups in the other BP and patient-reported outcomes. Incidence and severity of adverse events were similar between groups. Conclusions: SXC was well tolerated and demonstrated noninferior to losartan in BP lowering in patients with mild hypertension. SXC might be an alternative for mild hypertension, particularly for patients with a preference for natural medicine. Registration: URL: www.chictr.org.cn ; Unique identifier: ChiCTR-IPR-16008108.