Effects of Qingda granule on patients with grade 1 hypertension at low-medium risk: study protocol for a randomized, controlled, double-blind clinical trial

BACKGROUND: Numerous pre-clinical studies showed that Qingda granule (QDG) was effective in treating hypertension. This study aims to evaluate the efficacy and safety of QDG in reducing blood pressure among patients with grade 1 hypertension at low-medium risk. METHODS: The study is designed as a randomized, multi-center, double-blinded, non-inferiority clinical trial. Five hundred fifty-two patients with grade 1 hypertension at low-medium risk from 13 hospitals will be recruited and randomly assigned to the QDG group (n = 276, treated with valsartan capsule simulation agent and QDG) or control group (n = 276, treated with valsartan capsule and QDG simulation agent). The treatment period will be 4 weeks and the follow-up period will last 4 weeks after treatment. Primary outcome will be a decreased value of systolic blood pressure and diastolic blood pressure after treatment. And second outcome will include the decreased value of diastolic blood pressure and systolic blood pressure at the end of follow-up, the percentage of participants achieving normal blood pressure at the end of treatment and follow-up, the Hamilton Anxiety Scale and TCM syndrome scores at the end of treatment and follow-up, and levels of hypertensive hormones at end of treatment and follow-up. DISCUSSION: This study will provide initial evidence regarding the clinical efficacy and safety of QDG in treating grade 1 hypertension at low-medium risk. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2000033890. Registered on 15 June 2020. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-022-07006-0.