Analysis of Sanfeng Tongqiao Diwan in treating upper airway cough syndrome: issues & insights

We have recently read with great interest the article “Efficacy and safety of Sanfeng Tongqiao Diwan in the treatment of upper airway cough syndrome: a randomized, double-blind, placebo-controlled clinical study” (1), and we believe that this manuscript provides good clinical results for the treatment of upper airway cough syndrome (UACS). However, at the same time, we have the following questions about this manuscript:

Firstly, when the manuscript elaborates on the theoretical basis of traditional Chinese medicine for the treatment of UACS with Sanfeng Tongqiao Diwan, concepts such as “pathogenic wind invading the lungs”, “dredging collaterals, expelling wind, promoting the lungs, and relieving asthma” have not been fully integrated with the understanding of the pathogenesis of the disease and the mechanism of drug action in modern medicine (2). Although some pharmacological effects of each component (S. baicalensis, S. tenuifolia, A. sieboldii, and N. incisum) in the drug in modern medical research are mentioned, it does not clearly explain how these modern pharmacological effects correspond to the treatment principles in traditional Chinese medicine theory. Moreover, when introducing the pharmacological effects of the drug components, multiple effects are listed for each component, but the main and secondary roles of each component in the treatment of UACS and the way of their synergistic action are not clearly pointed out. Readers may be confused about the contributions and relationships of each component in the compound preparation and cannot clearly understand the core mechanism of the drug’s efficacy (3).

Secondly, the description of the use of dextromethorphan in the article is: “During the treatment period, the 2 groups were not given other antihistamines or TCMs, and dextromethorphan oral disintegrating tablet (30 mg) was prescribed as needed (tid).” However, the specific usage of dextromethorphan by the two groups of patients is not detailed in the article, such as the number of patients who actually used the drug, the distribution of usage frequency, the duration of use, and the specific impact of the use of dextromethorphan on the main results of the study (the efficacy evaluation of Sanfeng Tongqiao Diwan). This lack of clarity may have a certain impact on the interpretation of the research results and the accurate judgment of the drug’s efficacy, because dextromethorphan itself has an antitussive effect (4). If the usage situation is not clear, it is difficult to know exactly whether it interferes with the evaluation of the antitussive effect of Sanfeng Tongqiao Diwan. And the method of monitoring the compliance of drug taking is not described in detail. Whether patients take the drug on time and in the correct dosage may affect the treatment effect. If not strictly monitored, it may lead to result bias and cannot accurately reflect the true efficacy of the drug.

Thirdly, when discussing the 4 patients in the experimental group who did not respond to treatment, it is only speculated that it may be related to the scope of inflammation, but it does not further explore how to identify such patients before treatment, and whether there are other possible intervention measures or suggestions for adjusting the treatment plan for such patients. For the increase in blood eosinophil count in the placebo group, although it is mentioned that it may be related to uncontrolled inflammation, the potential impact of this result on the evaluation of the efficacy of the study drug and how to further monitor and handle such situations in subsequent studies are not deeply analyzed (5).

We would like to thank all the authors of this manuscript again for providing clinical ideas for the etiological and symptomatic treatment of UACS with Sanfeng Tongqiao Diwan, and at the same time establishing a relatively complete efficacy evaluation system, providing a basis for the integrated treatment of traditional Chinese and Western medicine and subsequent clinical and/or basic research.

Acknowledgments

Funding: The study was supported by the fifth batch of the National TCM Clinical Outstanding Talents Training Program [National TCM Education Letter (2022) No. 1] and Zhejiang Province Elderly Cardiopulmonary Diseases Traditional Chinese Medicine Innovation Team Project [Zhejiang Weifa (2023) No. 31].

Footnote

Provenance and Peer Review: This article was a standard submission to the journal. The article did not undergo external peer review.

Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2024-1938/coif). The authors report that this study was supported by the fifth batch of the National TCM Clinical Outstanding Talents Training Program [National TCM Education Letter (2022) No. 1] and Zhejiang Province Elderly Cardiopulmonary Diseases Traditional Chinese Medicine Innovation Team Project [Zhejiang Weifa (2023) No. 31]. The authors have no other conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Wang W, Xian M, Shi X, et al. Efficacy and safety of Sanfeng Tongqiao Diwan in the treatment of upper airway cough syndrome: a randomized, double-blind, placebo-controlled clinical study. J Thorac Dis 2023;15:1716-25. [Crossref] [PubMed]
2. Liu S, Zhu JJ, Li JC. The interpretation of human body in traditional Chinese medicine and its influence on the characteristics of TCM theory. Anat Rec (Hoboken) 2021;304:2559-65. [Crossref] [PubMed]
3. Zhou CF, Zhang JK. The present situation and prospects of researches on the pharmacology of compounded Chinese drugs. J Tradit Chin Med 1989;9:220-9.
4. Silva AR, Dinis-Oliveira RJ. Pharmacokinetics and pharmacodynamics of dextromethorphan: clinical and forensic aspects. Drug Metab Rev 2020;52:258-82. [Crossref] [PubMed]
5. O'Sullivan JA, Bochner BS. Eosinophils and eosinophil-associated diseases: An update. J Allergy Clin Immunol 2018;141:505-17. [Crossref] [PubMed]