Tanreqing injection for acute bronchitis disease: A systematic review and meta-analysis of randomized controlled trials

Background: Acute bronchitis (AB) is one of the common diseases. Tanreqing injection (TRQ) was widely used to treat patients with acute bronchitis, and many randomized controlled trials have been conducted to investigate its efficacy.

Objective: The purpose of this systematic review is to evaluate the efficacy and safety of TRQ for AB.

Methods: Eight English and Chinese electronic databases, up to October 2014, were searched to identify randomized controlled trials on TRQ for AB. Two reviewers independently extracted data and assessed the quality of each trial by using Cochrane handbook. Meta-analysis was carried out by using Review Manager software.

Result: A total of 49 trials with 5131 participants were collected. Data of three main outcomes were pooled and analyzed as following: (1) effective rates: TRQ versus antibiotics (RR 1.12; 95% CI 1.05, 1.18; P=0.0002); TRQ plus antiviral drugs versus antiviral drugs (RR: 5.12; 95% CI 3.03, 8.66; P<0.00001); TRQ plus antibiotics versus antibiotics (RR 3.46; 95% CI 2.59, 4.62; P<0.00001); TRQ versus antibiotics plus antiviral drugs (RR 2.03; 95% CI 1.10, 3.74; P=0.02); TRQ plus conventional therapy versus conventional therapy alone (RR 1.21; 95% CI 1.15, 1.27; P<0.00001). (2) Time for fever resolution: TRQ plus antiviral drugs versus antiviral drugs (MD: -1.08; 95% CI -1.59, -0.57; P<0.00001); TRQ plus antibiotics versus antibiotics (MD -1.33; 95% CI -1.81, -0.86; P<0.00001); TRQ versus antibiotics plus antiviral drugs (MD -0.88; 95% CI -1.25, -0.51; P<0.00001); TRQ plus conventional therapy versus conventional therapy alone (MD -1.06; 95% CI -1.13, -0.98; P<0.00001). (3) Resolution of cough: TRQ plus antiviral drugs versus antiviral drugs (MD: -2.09; 95% CI -3.11, -1.43; P<0.00001); TRQ plus antibiotics versus antibiotics (MD: -2.65; 95% CI -2.88, -2.42; P<0.00001); TRQ plus conventional therapy versus conventional therapy alone (MD -1.84; 95% CI -2.85, -0.83; P=0.0003). Four trials described the adverse drug reactions of TRQ, while no severe adverse drug reactions reported.

Conclusions: As a therapy for AB, TRQ has potentially beneficial effect in improving effective rates, reducing the time to resolution of fever, cough, crackles and absorption of shadows on X-ray. However, due to the limitations of methodological quality of the included trials, it is difficult to make a conclusive recommendation about TRQ treating patients with AB. Further rigorous clinical trials are warranted to evaluate the efficacy and safety of TRQ.