Exploring the Role of Suhuang Zhike Capsules in Cough Variant Asthma

Cough variant asthma (CVA) remains a persistent challenge for clinicians, marked by chronic, often nighttime cough that disrupts quality of life and may evolve into classic asthma. While inhaled corticosteroids remain a mainstay of therapy, symptom recurrence and concerns about long-term safety fuel an ongoing search for complementary strategies.

A recent large-scale, multicenter phase IV trial shines new light on the potential of Suhuang Zhike capsules—a traditional Chinese medicine (TCM) formulation—in the real-world management of CVA.

Conducted across 40 hospitals in China, this prospective, single-arm, open-label trial enrolled 1,033 patients with CVA. Patients took three capsules orally, three times daily for 14 days. Importantly, this design imposed no restrictions on concomitant therapies, reflecting real-world practice.

The primary outcome was the change in cough symptom scores at two weeks, while secondary outcomes measured rates and timing of cough disappearance, cough relief, and changes in TCM symptom scores. Safety monitoring included laboratory testing, adverse event (AE) reporting, and physician assessment.

Efficacy and Safety Highlights

Results were both clinically meaningful and statistically robust:

• Rapid symptom relief: The median time to noticeable cough improvement was just three days,. The median time to cough disappearance or near disappearance was 11 days.
• Durable effects: By day 14, 67 percent of patients achieved cough disappearance or near disappearance.
• Score reductions: Cough symptom scores decreased significantly from a baseline mean of 3.8, with a 2.9-point reduction by day 14 (P < 0.0001). Daytime and nighttime scores followed similar downward trends.
• Comprehensive improvements: Beyond cough, TCM symptom scores, which also tracked throat itching, expectoration, and shortness of breath, fell sharply by day seven and continued to improve through day 14 (P < 0.0001).

A subgroup analysis provided an unexpected twist: while patients on combined respiratory medications showed earlier reductions in cough scores, by days 13 to 14, the Suhuang Zhike–only group demonstrated significantly superior outcomes.

Safety findings were reassuring, with 12 percent of patients reporting any adverse events. Only 2.24 percent of cases were considered related to the study medication, most commonly gastrointestinal disturbances such as abdominal discomfort (0.88 percent) and nausea (0.78 percent). Other events were rare, including dizziness (0.19 percent), headache (0.10 percent), pruritus (0.10 percent), and palpitations (0.10 percent). Serious adverse events occurred in three patients (0.29 percent), but none were judged to be treatment-related.

Overall, these results are consistent with the known safety profile of the formulation and underscore its tolerability in a broad patient population, even among those receiving concomitant therapies.

Clinical Implications

Unlike earlier, smaller controlled studies, this investigation captured the variability of real-world practice, including patients with comorbidities and those using additional medications. The results provide solid evidence that Suhuang Zhike capsules can be a safe, effective adjunct or stand-alone option for CVA management, particularly in settings where guideline-recommended therapies may be insufficient or poorly tolerated.

References
Hongchun Z, Jian L, Sheng C, et al. Efficacy and safety of Suhuang Zhike capsule for cough variant asthma: a multicenter, single-arm, open-label phase IV real-world clinical trial. J Tradit Chin Med. 2025;45(4):817-828. doi:10.19852/j.cnki.jtcm.2025.04.011