[Randomized controlled study on suhuang zhike capsule for treatment of post-cold cough]

To observe the effect and safety of Suhuang Zhike Capsule (SZC) on post-cold cough.

The multi-centered randomized double-blinded clinical trial was adopted, and Zhike Ningsuo Capsule (ZNC) as the positive control drug, 280 patients were enrolled and assigned to two groups, the 210 patients (2 dropped out) in the treatment group were treated with SZC, and the 70 (1 dropped out) in the control group treated with ZNC, both at the daily dose of 3 capsules for three times, and the course for all patients was 7 days. The frequency, degree of cough as well as the condition of throat itching and expectoration were observed.

The program was completed in 204 patients of the treatment group and 67 in the control group. per-protocol (PP) analysis on cough showed the total effective rate and the cured-effective rate was 87.75 % and 58.82% in the treatment group respectively, which was superior to that in the control group, 76.12% and 34.33%, respectively (P < 0.05). intention-to-treat (ITT) analysis on cough also showed the similar results 87.02 % vs 75.36% for total effective rate, 57.42% vs 35.71% for the cured-effective rate (P < 0.05). The two indexes of effectiveness on disease analyzed by PP were 92.16 % and 60.29% in the treatment group, and 86.57% and 31.34% in the control group respectively (P < 0.05), and by ITT were 91.35 % and 59.62%, 85.51% and 30.43%, respectively (P < 0.05), both showed significant difference between groups only in cured-effective rate but not in the total effective rate (P > 0.05).

SZC is effective and safe in treating post-cold cough.