OBJECTIVE: To summarize the clinical efficacy characteristics of Suhuang Zhike capsule (苏黄止咳胶囊) and evaluate the incidence of adverse reactions in its broad clinical application.

METHODS: This was a multicenter, prospective, single-arm, open-label phase IV clinical trial. A total of 1100 patients diagnosed with cough variant asthma (CVA) and the Traditional Chinese Medicine (TCM) syndrome of wind evil invading the lung and lung Qi failing to propagate were planned for recruitment. Participants received Suhuang Zhike capsule orally, three capsules per dose, taken three times daily, for a treatment duration of 14 d. The primary outcome was the change in cough symptom scores from baseline to week 2. Cough severity was assessed twice daily. Additional evaluations included the rate and time of cough disappearance or basic disappearance rate, as well as the time of cough relief. TCM symptom scores were recorded at baseline and on days 7 and 14 of treatment. Safety assessments included monitoring for adverse events and conducting laboratory tests.

RESULTS: A total of 1033 patients with CVA from 40 hospitals across China were enrolled in the study. Of these, 1026 patients received the study medication and were included in the safety analysis. Fifty-four patients withdrew from the study, resulting in a drop-out rate of 5.23%. Treatment with Suhuang Zhike capsules significantly reduced cough symptom scores and improved cough-related symptoms in patients with CVA. The overall rate of cough disappearance or basic disappearance increased over the course of treatment, reaching 67.21% after 14 d. The median time of cough relief was 3 d, while the median time to cough disappearance or basic disappearance was 11 d. Additionally, the treatment led to reductions in TCM symptom scores and improvements in accompanying symptoms such as throat itching, expectoration, and shortness of breath. In terms of safety, no serious adverse events were reported. The incidence of related adverse events (AEs) was 2.24% (23 cases, 30 events). The incidence of adverse reactions listed in the drug’s instructions was 2.14%. Other related AEs not listed in the drug’s instructions occurred in 0.39% of patients and included dizziness (0.19%), headache (0.10%), pruritus (0.10%), and palpitation (0.10%).

CONCLUSION: Suhuang Zhike capsules demonstrated good efficacy and safety for the treatment of CVA. These findings offer valuable clinical evidence to support their broader application in routine clinical practice.