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.
Keywords: blood pressure; hypertension; losartan; medicine, Chinese traditional; randomized controlled trial.