Chinese herbs in treatment of postinfectious cough: A multi-centre, randomized, double-blind, placebo-controlled trial

Backgroud: Postinfectious cough (PIC) is troublesome when cough persists and adversely affects quality of life (QOL), but there is no reliable and safe medical treatment available. Objectives: T o investigate the efficacy and safety of a Chinese herbal formula Qingfeng Ganke granule (QGG) in treatment of PIC, and to determine whether QGG could improve QOL in patients with PIC. Methods: In a multi-centre, randomized, double-blind, placebo-controlled trial, patients aged 18 to 65 years old were randomly assigned to either group A (6 g of QGG plus 6 g of QGG analogue), group B (12 g of QGG), or group C (12 g of QGG analogue), twice daily for 10 days. All patients finished Cough Quality of Life Questionnaire (CQLQ) at day 1 and day 10. All patients recorded cough frequency and severity on diary card during treatment. The trial was registered with the Chinese Clinical Trial Registry (No.ChiCTR-TRC-12002297). Results : A total of 180 eligible subjects were randomly (1:1:1) assigned to three treatment groups and 12 patients withdrew from the study. QGG significantly improved CQLQ scores compared with placebo (group A: -6.17 [95% CI, -10.4 to -1.88]; P = 0.0258; group B: -9.65 [95% CI, -13.9 to -5.4]; P = 0.0003). There were also significant differences in median duration of cough recovering (> 10 days vs. 8 days vs. >10 days; P < 0.0001) and median duration of cough alleviating (4 days vs. 4 days vs. 6 days; P < 0.0001). Adverse events were reported similarly in three groups (7.02% vs. 7.02% vs. 1.69%; P = 0.3313). Conclusions: QGG improved cough and cough-related quality of life in patients with PIC. QGG can be a clinically valuable intervention in the management of PIC.