Abstract
Chronic obstructive pulmonary disease (COPD) is a severe condition that leads to premature mortality and places a significant financial burden on healthcare systems. An adjunctive therapy in COPD includes the simultaneous administration of astragalus injection and ambroxol hydrochloride. Despite its widespread use, the effectiveness of this combined approach in COPD treatment has not been systematically evaluated. Thus, we conducted a systematic review and meta-analysis to assess the efficacy of combining astragalus injection with ambroxol hydrochloride as an adjuvant treatment for COPD. Six electronic databases were used to search for relevant randomized controlled trials, and data analysis was conducted using Review Manager 5.4. A total of 14 randomized controlled trials were included, involving 1070 patients who met the criteria. The results of the meta-analysis indicated that the combination of astragalus injection with ambroxol hydrochloride as an adjuvant treatment can improve various clinical parameters in patients with COPD compared to conventional treatment alone. These parameters include the clinical effective rate (OR = 5.44, 95% CI 3.51–8.43, I2 = 0%), partial pressure of oxygen in artery (MD = 1.12, 95% CI 0.87–1.36, I2 = 5%), partial pressure of carbon dioxide in artery (MD = − 1.43, 95% CI − 1.65 to − 1.21, I2 = 0%), forced expiratory volume in one second (MD = 0.30, 95% CI 0.18–0.42, I2 = 0%), percentage of forced expiratory volume in one second (MD = 16.18, 95% CI 12.60–19.76, I2 = 82%), forced vital capacity (MD = 0.33, 95% CI 0.21–0.45, I2 = 36%), hemoglobin (MD = − 16.17, 95% CI − 20.84 to − 11.51, I2 = 29%), and the ratio of forced expiratory volume in one second to forced vital capacity (MD = 2.51, 95% CI − 0.05 to 5.06, I2 = 0%). The combination of astragalus injection and ambroxol hydrochloride could be a selection of COPD patients as an adjuvant treatment. However, further validation is required to evaluate the effectiveness of combining astragalus injection and ambroxol hydrochloride as an adjunctive treatment for patients with COPD.
Similar content being viewed by others
Introduction
Chronic obstructive pulmonary disease (COPD) is a global disease with 3.97 million new cases reported in China in 2019. The incidence of COPD tends to increase with age1. COPD is a preventable and treatable disease, but airflow restriction is progressive and affects patients' quality of life1. At present, the primary treatment methods for COPD include anti-infection medications, cough suppressants, expectorants, bronchodilators, and spasmolytics. Although medical technology continues to improve, COPD is still a significant medical burden1.
Ambroxol hydrochloride is a commonly used drug in the adjunctive treatment of COPD2. It can effectively alleviate the clinical symptoms and improve lung function in patients with COPD2. Astragalus injection is a traditional Chinese medicine injection that can be used in conjunction with conventional treatment to aid in the treatment of COPD3,4. The combination of traditional Chinese medicine preparation and conventional treatment can reduce the number of acute exacerbations of COPD and improve the clinical efficacy of COPD treatment5,6. Clinical researchers in China have used astragalus injection in combination with ambroxol hydrochloride as an adjuvant treatment for COPD7. However, the effects of combining astragalus injection with ambroxol hydrochloride on patients with (COPD) have never been systematically evaluated. To assess the therapeutic efficacy of astragalus injection combined with ambroxol hydrochloride as an adjuvant treatment for COPD, we conducted a systematic review and meta-analysis by summarizing relevant randomized controlled trials (RCTs).
Methods
This study followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) project, and all study procedures were conducted in accordance with PRISMA requirements8. The systematic review has been registered on the International Prospective Register of Systematic Reviews (PROSPERO), and the ID is CRD42023421010.
Information sources and search strategies
The databases used were PubMed, China Biomedical Literature Database (CBM), Wan Fang Database, Embase, Web of Science, and the China National Knowledge Infrastructure (CNKI). The literature search strategy is ("Astragalus injection") AND ("Ambroxol hydrochloride") AND ("COPD" OR "Chronic obstructive pulmonary diseases"). To ensure that no important literature is missed, we conducted a thorough literature search using the strategy shown in Supplementary Material. The retrieval date was set from the database's establishment to October 26, 2023. There were no language restrictions.
Inclusion and exclusion criteria
Inclusion criteria: (a) Type of study (S): The included study was a randomized controlled trial; (b) Type of participant (P): Adult patients clinically diagnosed with COPD and hospitalized for COPD; (c) Type of intervention (I): The experimental group was given Astragalus injection and Ambroxol hydrochloride and conventional treatment, and the administration was via an intravenous drip; (d) Type of comparator (C): The control group received conventional treatment; (e) Type of prognostic measurement (O): These studies included one of the following outcomes: clinical effective ratio (CER), lung function, and arterial blood gas analysis, hemoglobin.
Exclusion criteria: (a) Unable to extract sufficient data for statistical aggregation; (b) Outcome measurement and conclusion were inconsistent; (c) Duplicate published or duplicated data; (d) The original data was not available.
The type of the outcome measurement
The clinically effective ratio (CER) was the primary outcome, and forced expiratory volume in one second (FEV1), percentage of forced expiratory volume in one second (FEV1%), forced vital capacity (FVC), partial pressure of oxygen in artery (PaO2), partial pressure of carbon dioxide in artery (PaCO2), the ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC), hemoglobin, were the secondary outcomes.
Selection of studies and extraction of data
Two reviewers (CH and ZBZ) reviewed potentially eligible studies and documented the selection process independently, and then completed the PRISMA flowchart. The data was independently extracted by (ZBZ and XBZ) using the extraction table. The information retrieved was as follows: Name of the first author, year of publication, study design, the sample size of the trial, the mean age of the participants, the interventions of the experimental group and the control group, duration, and outcomes. Differences in the retrieved information were resolved through consulting with LLY and RG.
Risk of bias assessment
The quality of the methods in each trial was scored independently scored by two evaluators (LLY and ZBZ), which included seven domains: appropriate sequence generation, hidden allocation, blinding of participants and people, incomplete outcome data, selective reporting, and other biases. Three levels were used to assess the quality of the method: "low bias risk" ( +), "high bias risk" (−), and "uncertain bias risk" (?). We discussed the differences with other researchers (CH, XBZ, and RG) to reach a consensus.
Data synthesis and analysis
The Review Manager 5.4 was used for the meta-analysis. Dichotomous data were expressed as odds ratio (OR). Continuous data were expressed as mean difference (MD) with a 95% confidence interval when the units of measurement for the outcome variable are the same. When I2 > 50% and P < 0.05, there was significant heterogeneity between studies, and a random effects model was used for meta-analysis. When there was no heterogeneity between studies, the fixed effects model was used to summarize OR and MD. Qualitative analysis of data that cannot be included in the meta-analysis.
Sensitivity analysis
Sensitivity analysis was conducted to assess the robustness of the pooled OR values and the pooled MD values by excluding each trial.
Risk of publication bias
As more than 10 studies were included, we would test for potential publication bias using a funnel plot.
Quality assessment of the evidence
Two reviewers (CH and ZBZ) used GRADE prolifer to assessed the grade of each evidence independently. A third reviewer (LLY) determined the differences in the assessments. Four levels of "high", "medium", "low", and "very low" were used to evaluate the quality of evidence. If the sample size of the trial was less than 400, or the pooled values with high sensitivity, the quality of the study would be reduced by one grade.
Results
Description of studies
We identified 1542 related studies from the databases. Thereafter, we obtained 24 articles after excluding 653 duplicated articles and 865 articles that did not meet the inclusion criteria. After further review of the full text, 14 studies were excluded and 10 randomized controlled trials (n = 1070) were finally included, all of which were from China. The literature selection process is displayed in Fig. 1, and the general characteristics of studies are listed in Table 1.
Risk of bias in the included studies
Figure 2a and Fig. 2b summarized the bias risk assessment for 14 RCTs. From the 14 RCTs, eight studies had no specific methods3,4,7,11,12,14,15,18, three studies used random number tables9,10,13, one study used random blind selection16, one study used a double-blind method19, and one study used a lottery for random allocation17. None of the 14 studies mentioned blinding the participants, personnel, or assessment outcomes. Data from the 14 studies were complete and did not exist other risks of bias.
Primary outcome
Clinical effective ratio (CER)
Fourteen RCTs (N = 1070) reported the effect of astragalus injection combined with ambroxol hydrochloride on the clinical effective ratio (CER) of COPD. CER = (number of obvious effective cases + number of effective cases) / total number of people in each group × 100%. The results of the data analysis show that the combination of astragalus injection and ambroxol hydrochloride injection with conventional treatment significantly improved CER, compared to conventional treatment alone (OR = 5.44, 95% CI: 3.51–8.43, P < 0.00001). There was no heterogeneity among the fourteen studies (P = 0.97, I2 = 0%), and a fixed-effects model was used for the meta-analysis (Fig. 3).
Secondary outcomes
Pulmonary function: FVC, FEV1, FEV1/FVC, and FEV1%
Five RCTs (N = 422) reported FVC9,12,13,14,19. Data analysis revealed that the combination of astragalus injection and ambroxol hydrochloride with conventional treatment can improve FVC in patients with COPD compared to conventional treatment alone (MD = 0.33, 95% CI 0.21–0.45, P < 0.00001). There was no heterogeneity among the five studies (P = 0.18, I2 = 36%), and a fixed-effects model was used for the meta-analysis (Fig. 4a).
Five RCTs (N = 350) reported FEV14,9,11,12,14. Data analysis revealed that the combination of astragalus injection and ambroxol hydrochloride as an adjuvant treatment significantly improved FEV1 compared to conventional treatment alone (MD = 0.30, 95% CI 0.18–0.42, P < 0.0001). There was no heterogeneity among the five studies (P = 0.99, I2 = 0%), and a fixed-effects model was used for data analysis (Fig. 4b).
Four RCTs (N = 300) reported the FEV1/FVC3,10,15,18. Data analysis revealed that the combination of astragalus injection and ambroxol hydrochloride can improve the FEV1/FVC compared to conventional treatment alone (MD = 2.51, 95% CI − 0.05 to 5.06, P = 0.05). No heterogeneity was found among the four studies (P = 0.94, I2 = 0%), and data were analyzed using a fixed-effects model (Fig. 4c).
Ten RCTs (N = 794) reported FEV1%3,9,10,12,13,14,15,16,18,19. Data analysis revealed that the combination of astragalus injection and ambroxol hydrochloride with conventional treatment significantly improved patients’ FEV1% compared to conventional treatment alone (MD = 16.18, 95% CI 12.60–19.76, P < 0.00001). There was significant heterogeneity among the ten studies (P < 0.00001, I2 = 82%), and a random-effects model was used for the meta-analysis (Fig. 4d). Sensitivity analysis revealed that heterogeneity originated from the Zhang 2017 (Table 2), the source of heterogeneity may be the dosage of astragalus injection.
Arterial blood gas analysis: PaO2, PaCO2
PaO2 was reported in seven RCTs (N = 566)3,10,12,13,15,16,18. Data analysis revealed that the combination of treatments significantly improved patients' PaO2 compared to conventional treatment alone (MD = 1.12, 95% CI 0.87–1.36, P < 0.00001). There was no significant heterogeneity among the seven studies (P = 0.39, I2 = 5%), and a fixed-effects model was used (Fig. 4e).
PaCO2 was reported in seven RCTs (N = 566)3,10,12,13,15,16,18. Data analysis revealed that the combination significantly improved patients' PaCO2 compared to conventional therapy (MD = − 1.43, 95% CI − 1.65 to − 1.21, P < 0.00001). There was no heterogeneity among the seven studies (P = 0.43, I2 = 0%), and a fixed-effects meta-analysis was used (Fig. 4f).
Hemoglobin
Three RCTs (N = 264) reported the effects of astragalus injection combined with ambroxol hydrochloride on the hemoglobin levels of patients with COPD9,12,13. Data analysis showed that, compared to conventional treatment alone, the combination therapy significantly down regulated the hemoglobin levels of patients with COPD (MD = − 16.17, 95% CI − 20.84 to − 11.51, P < 0.00001). There was no heterogeneity among the seven studies (P = 0.24, I2 = 29%), and a fixed-effects meta-analysis was used (Fig. 4g).
Sensitivity analysis
We use sensitivity analysis to assess the robustness of merged data and investigate the sources of heterogeneity. Through sensitivity analysis, it was found that, in addition to FEV1/FVC, the pooled mean difference (MD) values of FVC, FEV1, PaO2, PaCO2, and the pooled odds ratio (OR) values of CER are robust. Sensitivity analysis results of FEV1% and FEV1/FVC are shown in Table 2.
Publication bias analysis
As shown in Fig. 5, the funnel plot of the CER is approximately symmetric, indicating no publication bias.
Quality of evidence
We evaluated the quality of evidence. Due to unclear bias risk in research methods and the medication and dosage of routine therapy are unclear, the quality of evidence for CER, PaO2, PaCO2 and FVC has been downgraded by two grade. The quality of evidence for FEV1 has been downgraded by two levels due to unclear bias risk in research methods and a sample size of less than 400. Because of the unclear bias risk in research methods, a sample size of less than 400, and the high sensitivity of the pooled MD values, the quality of evidence for hemoglobin, FEV1/FVC, and FEV1% is considered to be very low. The comprehensive results are presented in Table 3, providing a clear depiction of the quality of the evaluated evidence.
Discussion
In the study, we conducted a systematic evaluation of the clinical efficacy of astragalus injection combined with ambroxol hydrochloride as an adjuvant treatment for COPD. Additionally, we evaluated the therapeutic impact of this combination on pulmonary function and arterial blood gas analysis.
In terms of clinical efficacy, the combination of astragalus injection with ambroxol hydrochloride as adjuvant treatment significantly improved the CER in COPD. Seven studies obtained CER from clinical symptoms such as cough, phlegm, and shortness of breath, as well as from chest X-rays4,10,11,14,16,17,19. Three studies obtained CER based on cough, sputum volume, and pulmonary rales7,15,18. Two studies obtained CER according to the Guidelines for Clinical Research on expectorant cough suppressants12,13. One study obtained the CER based on improvements in body temperature and coughing9. One study did not describe the method of obtaining CER3. In future studies, the method of obtaining CER should be standardized, such as the COPD Assessment Test (CAT). In terms of lung function, the combination of astragalus injection and ambroxol hydrochloride can improve FVC, FEV1/FVC, FEV1, and FEV1% in COPD patients as an adjuvant treatment. However, the quality of evidence for FEV1% and FEV1/FVC is very low. In terms of arterial blood gas analysis, the combination of astragalus injection and ambroxol hydrochloride significantly improved the levels of PaO2 and PaCO2 in patients with COPD.
Although no adverse effects were reported in the 14 studies, early studies indicated that astragalus injection may have some side effects20. Hence, further research is needed to determine the safety of combining astragalus injection with ambroxol hydrochloride in COPD patients.
The pathogenesis of COPD is related to chronic inflammation, oxidative stress, and immune imbalance. Cytokine release and oxidative stress are induced by airborne particles 2.5 (PM2.5), which can exacerbate COPD conditions21,22. The Th17/Treg ratio in the lungs of COPD patients is unbalanced, and the release of the cytokine IL17 by Th17 cells leads to the exacerbation of COPD symptoms23. Astragaloside IV, one of the main components of Astragalus injection, has anti-inflammatory, antioxidant, and immune regulatory effects24. Additionally, astragaloside can activate the AMPK/mTOR signaling pathway and reduce lung inflammation and injury induced by PM2.525. Astragaloside IV also inhibits the cellular response of Th1726. In clinical studies, ambroxol hydrochloride has been shown to be an effective adjunctive therapy in reducing inflammation, alleviating clinical symptoms, and improving pulmonary function2. Traditional Chinese medicine believes that deficiency in the spleen and lungs is one of the causes of COPD27. Astragalus can tonify the qi of the lungs and spleen. Clinical studies have shown that astragalus injection can enhance lung function in patients with COPD28.These findings might explain the enhanced clinical effectiveness of combining astragalus injection with ambroxol hydrochloride in COPD.
However, this study had some limitations. First, the number of relevant studies included was only 14, all of which were published in China, and did not describe whether these patients were in a stable or acute phase of COPD. Additionally, the overall quality of these studies was not high, which diminished the credibility of the findings. Second, although all the studies used random assignment, only six studies provided specific explanations, which may increase the risk of selection bias. Thirdly, None of the studies indicated whether double-blind trials were conducted, and the overall quality of the 14 included studies was low. Fourth, the pooled mean MD value for FEV1/FVC are highly sensitive, which reduces the quality of the evidence. Furthermore, 14 of the included studies did not specify the use of conventional treatment drugs and dosages, which undermines the credibility of the evidence. In future studies, more clinical trials are needed to verify the clinical efficacy of combining astragalus injection with ambroxol hydrochloride as adjuvant therapy in patients with COPD.
Conclusion
In conclusion, as an adjuvant treatment, the combination of astragalus injection and ambroxol hydrochloride significantly improves the clinical symptoms of patients with COPD. This suggests that combining astragalus injection with ambroxol hydrochloride could be a viable adjuvant treatment option for patients with COPD. However, due to the limitations of the trials, further validation is required to evaluate the effectiveness of combining astragalus injection with ambroxol hydrochloride for patients with COPD. Additionally, future trials should preferably employ a clear randomization method and incorporate a double-blind test.
Data availability
Raw data relevant to the conclusions of this study will be provided by the corresponding authors upon reasonable request.
Abbreviations
- COPD:
-
Chronic obstructive pulmonary disease
- FEV1:
-
Forced expiratory volume in one second
- FEV1%:
-
Percentage of forced expiratory volume in one second
- FVC:
-
Forced vital capacity
- FEV1/FVC:
-
The ratio of forced expiratory volume in one second to forced vital capacity
- PaO2 :
-
Partial pressure of oxygen in artery
- PaCO2 :
-
Partial pressure of carbon dioxide in artery
References
Yin, P. et al. The burden of Copd in China and its provinces: Findings from the global burden of disease study 2019. Front. Public Health 10, 859499 (2022).
Li, Z. The effect of adjuvant therapy with ambroxol hydrochloride in elderly chronic obstructive pulmonary disease patients. Am. J. Transl. Res. 13, 9285–9295 (2021).
Dai, L. R. Clinical efficacy of ambroxol hydrochloride combined with astragalus injection in the treatment of chronic obstructive pulmonary disease. Med. J. Chin. People Health 26, 40–41 (2014).
Ni, X. Z. Clinical study of ambroxol hydrochloride combined with astragalus injection in the treatment of chronic obstructive lung disease. Strait Pharm. J. 25, 119–120 (2013).
Wen, G. et al. Effectiveness of chinese herbal medicine combined with conventional medicine on acute exacerbation of chronic obstructive pulmonary disease: A systematic review and meta-analysis. J. Tradit. Chin. Med. 43, 212–220 (2023).
Huang, P., Lin, X., Liu, Y. & Hou, Z. The efficacy and safety of combined traditional Chinese and western medicine in the treatment of chronic obstructive pulmonary disease complicated with respiratory failure: A systematic review and meta-analysis study. Ann. Palliat. Med. 11, 1102–1111 (2022).
Tang, S. Effect of ambroxol hydrochloride injection and astragalus membranaceus injection on acute exacerbation of chronic obstructive pulmonary disease. Contemp. Med. Sympos. 14, 163–164 (2016).
Page, M. J. et al. The Prisma 2020 Statement: An updated guideline for reporting systematic reviews. BMJ-Brit. Med. J. 372, n71 (2021).
Ibaditi, A. Effect of ambroxol hydrochloride combined with astragalus injection on chronic obstructive pulmonary disease. Guide China Med. 15, 41–42 (2017).
Guan, Q. L. Effect Evaluation of Ambroxol Hydrochloride Combined with Astragalus Injection in Treatment of Chronic Obstructive Pulmonary Disease. China Health Vison. 101 (2018).
Hu, Z. & Liu, F. Clinical study of ambroxol hydrochloride combined with astragalus injection in the treatment of chronic obstructive pulmonary disease. Guide China Med. 10, 469–470 (2012).
Jing, X. & Wang, X. H. Clinical effect of mucosolvan and astragalus injection on chronic obstructive pulmonary disease. J. Modern Clin. Med. 34, 179–180 (2008).
Xie, L. J. & Wang, G. F. Clinical effect analysis on Chinese and western medicine combination for treating chronic obstructive pulmonary disease. J. Mod. Med. Health 28, (2012).
Song, R. & He, J. F. Clinical research of ambroxol hydrochloride combined with astragalus injection in treatment of Copd. J. Med. Forum 34, 27–28 (2013).
Yu, X. Effect of ambroxol hydrochloride combined with astragalus injection on chronic obstructive pulmonary disease. Pract. J. Cardiac Cerebral Pneumal Vasc. Dis. 21, 94–95 (2013).
Wang, L. Clinical efficacy of ambroxol hydrochloride combined with astragalus injection in the treatment of Copd. Healthful Friend 10, 79–80 (2020).
Wang, X. J. & Yang, F. Clinical efficacy of ambroxol hydrochloride combined with astragalus injection in the treatment of chronic obstructive pulmonary disease. Biotech World. 219 (2016).
Zhang, X. Effect of astragalus injection combined with ambroxol hydrochloride on chronic obstructive pulmonary disease. J. Ningxia Med. Univ. 37, 1345–1346 (2015).
Zhang, J. Clinical effect of ambroxol hydrochloride combined with astragalus injection on patients with Copd. Nei Mongol J. Tradit. Chin. Med. 36, 37–38 (2017).
Wang, L. et al. Adverse drug reactions and adverse events of 33 varieties of traditional Chinese medicine injections on national essential medicines list (2004 Edition) of China: An overview on published literatures. J. Evid.-Based Med. 3, 95–104 (2010).
Wang, Q. & Liu, S. The effects and pathogenesis of Pm2.5 and its components on chronic obstructive pulmonary disease. Int. J. Chronic Obstr. 18, 493–506 (2023).
Li, R., Zhou, R. & Zhang, J. Function of Pm2.5 in the pathogenesis of lung cancer and chronic airway inflammatory diseases. Oncol. Lett. 15, 7506–7514 (2018).
Ritzmann, F. & Beisswenger, C. Preclinical studies and the function of Il-17 cytokines in Copd. ann. Anat. 237, 151729 (2021).
Zhang, J., Wu, C., Gao, L., Du, G. & Qin, X. Astragaloside Iv derived from astragalus membranaceus: A research review on the pharmacological effects. Adv. Pharmacol. 87, 89–112 (2020).
Wang, Z. et al. Astragaloside Iv pre-treatment attenuates Pm2.5-induced lung injury in rats: Impact on autophagy, apoptosis and inflammation. Phytomedicine 96, 153912 (2022).
Zhong, Y. et al. Astragaloside iv alleviates ulcerative colitis by regulating the balance of Th17/Treg cells. Phytomedicine 104, 154287 (2022).
Peng, X., Liu, J., Luan, Z. & Feng, J. Pathogenesis of Airway Mucus Hypersecretion in Chronic Obstructive Pulmonary Disease and Intervention Oftraditional Chinese Medicine: a Review. Chinese Journal of Experimental Traditional Medical Formulae. 1–13 (2023).
Chu, X. & Chen, L. Effect of astragalus injection on pulmonary function in patients with chronic obstructive pulmonary disease. Pharmacol. Clin. Chin. Materia Medica 32, 156–159 (2016).
Author information
Authors and Affiliations
Contributions
T.S. designed the study, reviewed the manuscript, and supervised the study. Z.B.Z. and L.L.Y. performed literature search. Z.B.Z. and C.H. performed article selection. C.H. and R.G. assessed methodological bias risk. Z.B.Z. and X.B.Z. performed data extraction. C.H. and Z.B.Z. conducted meta-analyses and assessed study quality. Z.B.Z. and L.L.Y. drafted the manuscript. X.B.Z. provided us with methodological help.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Publisher's note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary Information
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
About this article
Cite this article
Zhou, Z., Yang, L., Hu, C. et al. The combination of astragalus injection and ambroxol hydrochloride in the adjuvant treatment of COPD: a systematic review and meta-analysis. Sci Rep 13, 22077 (2023). https://doi.org/10.1038/s41598-023-49421-6
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s41598-023-49421-6
- Springer Nature Limited