Background
Chronic obstructive pulmonary disease (COPD), a common respiratory disease, can be effectively treated by traditional Chinese medicine (TCM). Qingfei Huatan, a TCM formula, has been reported to effectively alleviate the clinical symptoms of COPD patients. However, there is a lack of multi-centre, randomised, double-blind, controlled clinical trials documenting the clinical efficacy and safety of this formula in the treatment of acute exacerbation of COPD (AECOPD).
Objective
This study evaluated the efficacy and safety of Qingfei Huatan formula in the treatment of AECOPD, thereby providing high-quality clinical evidence.
Design, setting, participants and interventions
A total of 276 patients with AECOPD were included in this multi-centre, randomised, double-blind, placebo-controlled trial and were randomised into treatment and control groups at a ratio of 1:1. Patients in the treatment and control groups took Qingfei Huatan granules or simulated Qingfei Huatan granules twice a day, for 14 days, in addition to Western medicine treatment. All patients were followed up for 3 months.
Main outcome measures
The primary outcome was time taken to symptom stabilisation. The secondary outcomes included duration of antibiotic use, clinical symptom and sign score, TCM syndrome score, dyspnoea score, and quality of life (QOL) score. Meanwhile, the safety of the formula was assessed through routine urine and stool tests, electrocardiograms, liver and kidney function tests, and the observation of adverse events throughout the trial.
Results
The time taken for effective stabilisation (P < 0.05) and obvious stabilisation (P < 0.01), and the duration of antibiotic use (P < 0.05) were significantly shorter in the treatment group than in the control group. On days 6, 9, 12 and 14 of treatment, clinical symptom and sign score decreased in both groups, particularly in the treatment group (P < 0.01). On days 9, 12 and 14 of treatment, the TCM syndrome scores of both groups were reduced (P < 0.01), with more significant reductions in the treatment group. At 3 months after the end of treatment, the treatment group continued to have lower clinical symptom and sign score and TCM syndrome score than the control group (P < 0.01). On days 6, 9, 12 and 14 of treatment, dyspnoea and QOL scores were markedly reduced in the two groups (P < 0.05 and P < 0.01, respectively), especially in the treatment group. At 3 months after the end of treatment, dyspnoea and QOL scores were lower in the treatment group than those in the control group (P < 0.01). No serious adverse events were observed in either group.
Conclusion
The Qingfei Huatan formula can effectively shorten the duration of AECOPD and antibiotic use, significantly relieve clinical symptoms, and increase QOL for AECOPD patients, with a favourable safety profile. These results suggest that this formula can be used as a complementary treatment for AECOPD patients.
Trial registration: The protocol was registered at the Chinese Clinical Trial Registry (ChiCTR1900026576).

Key words: Acute exacerbation of chronic obstructive pulmonary disease, Clinical trial, Syndrome of phlegm-heat congesting lung, Qingfei Huatan formula, Traditional Chinese medicine