Effects of Dangguixu-san in patients with acute lateral ankle sprain: a randomized controlled trial

BACKGROUND: Dangguixu-san (DS), a herbal extract, is widely used in Korean medicine to treat pain and swelling caused by ankle sprain. However, there is insufficient evidence regarding the effects of DS on ankle sprains. Accordingly, we assessed the efficacy and safety of DS for the treatment of acute lateral ankle sprain (ALAS). METHODS: This study was a multicenter (two Korean hospitals), randomized, double-blind, placebo-controlled, parallel-arm clinical trial with a 1:1 allocation ratio that included a per-protocol analysis and sub-analysis based on symptom severity. Forty-eight participants (n = 28 at Semyung University Korean Medicine Hospital in Chungju; n = 20 at DongShin University Gwangju Korean Medicine Hospital) with grade I or II ALAS that occurred within 72 h before enrollment were randomized to a DS (n = 24) or placebo (n = 24) group. Both groups received acupuncture treatment once daily for 5 consecutive days and the trial medication (DS/placebo capsule) three times a day for 7 consecutive days. Primary (visual analog scale [VAS] scores for pain) and secondary (Foot and Ankle Outcome Scores [FAOS], edema, and European Quality of Life Five-Dimension-Five-Level Scale [EQ-5D-5L] scores) outcome measures were recorded at baseline (week 0), the end of the intervention (week 1), and 4 weeks after treatment completion (week 5). RESULTS: Forty-six participants completed the trial (n = 23 each). Changes in VAS scores, FAOS Symptom/Rigidity, and FAOS Ache from week 1 to week 5 showed significant differences between the two groups. Sub-analyses showed significant differences in changes of FAOS Ache (week 0 to week 5) and VAS scores, total FAOS, and EQ-5D-5L scores (week 1 to week 5) between the two subgroups (grade II). There were no adverse events and significant negative changes in clinical laboratory parameters in both groups. CONCLUSIONS: Overall, the results of this study are in favor of DS combined with acupuncture and suggest that DS combined with acupuncture is a safe treatment with positive long-term effects in terms of pain reduction and symptom alleviation in patients with grade I or II ALAS. TRIAL REGISTRATION: Clinical Research Information Service KCT0002374. Registered on July 11, 2017; retrospectively registered. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-021-05135-6.