Effects of So-cheong-ryong-tang and Yeon-gyo-pae-dok-san on the common cold: Randomized, double blind, placebo controlled trial

Aim of the study: So-cheong-ryong-tang (SCRT) and Yeon-gyo-pae-dok-san (YPS) extracts are widely used in treatment of the common cold. The purpose of this study is to evaluate the efficacy of SCRT and YPS on the common cold. Methods: Four hundred eighty participants with symptoms of the common cold within 48 h were recruited for this randomized, double-blind, placebo-controlled trial. SCRT extract and YPS extract were put in gelatin capsules and orally administered 3 times a day. The pattern of participants was determined according to the Questionnaire for Common Cold Pattern Identification (QCCPI), and the severity of illness was assessed by Wisconsin Upper Respiratory Symptom Survey-21 Korean version (WURSS-21-K) every 7 days. Results: The test and control groups were not significantly different in gender, age, smoking history, and baseline score of WURSS-21-K at the time of enrollment. SCRT treatment significantly decreased the total WURSS-21-K score on the 6th and 7th day (p < 0.05) of the enrollment compared with the placebo group. YPS treatment decreased the total WURSS-21-K score on the 5th and 6th day (p < 0.05 vs. the placebo group) of the enrollment. In the patients with Wind-cold pattern cold, SCRT significantly decreased the total WURSS-21-K score from 4th to 8th day (p < 0.05). and YPS significantly decreased the total WURSS-21-K score from 4th to 6th day (p < 0.05). For the Wind-heat pattern cold, neither SCRT nor YPS group showed significant difference from the placebo group. SCRT and YPS did not significantly decrease the time to complete resolution of the cold symptoms. Conclusions: SCRT and YPS have beneficial, albeit limited, effects on common cold patients, especially those with the Wind-cold pattern cold. (C) 2010 Elsevier Ireland Ltd. All rights reserved.