<正>Objective:To explore the effect of Tanreqing Injection(痰热清注射液,TRQI) on the treatment of acute exacerbation of chronic obstructive pulmonary disease(AECOPD) with Chinese medicine syndrome of retention of phlegm and heat in Fei(痰热阻肺证,RPHF).Methods:In a prospective randomized controlled clinical trial,90 patients with AECOPD of RPHF syndrome were randomly assigned to 3 groups,TRQI and controls A and B,each with 30 cases.The TRQI group was administered with the intravenous injections of 20 mL TRQI once a day and conventional Western medicine treatment.Control group A was administered with the intravenous injection of 15 mg ambroxol hydrochloride twice a day and conventional Western medicine treatment,and control group B was administered with conventional Western medicine treatment only.The treatments were administered for 10 days.Chinese medical symptoms and signs were scored,and plasma concentrations of interleukin(IL)-8 and neutrophil elastase(NE) were recorded.Results:(1) The Chinese medical symptoms (cough,sputum amount,expectoration,dyspnea and fever) and signs(tongue and pulse) improved significantly in the TRQI group(P<0.05 or P<0.01),and improvements in cough,sputum amount and expectoration were better in the TRQI group than control group B(P<0.05);there was no significant difference between the TRQI group and control group A(P>0.05).The sign of tongue was also improved significantly in the TRQI group (P<0.05).(2) The overall effects in the TRQI group and control group A were significantly better than in control group B(P<0.05),with no significant differences between the TRQI group and control group A(P>0.05).There was no significant difference in the total effective rate among the three groups(P>0.05).(3) After treatment, the plasma concentrations of IL-8 and NE decreased in the TRQI group and control group A(P<0.05),and the concentration of IL-8 in control group B decreased(P<0.05).The difference in IL-8 was greater in the TRQI group than in control group A and B before and after treatment,and the change in NE was greater in control group A than in the TRQI group and control group B,but there was no statistical significance among the three groups with regards to the change in IL-8 or NE(P>0.05).Conclusion:TRQI could improved the Chinese medical signs and symptoms in the patients with AECOPD,possibly because of the decreasing plasma levels of IL-8 and NE which could improve response to airway inflammation and mucus hypersecretion.