Efficacy and safety of Onkyeong-tang in treating cold hypersensitivity in the feet of Korean women: protocol for a double-blind, randomized, placebo-controlled, parallel-group, multicenter clinical study

Background Cold hypersensitivity in the hands and feet (CHHF) commonly affects Asian women, especially Korean women, and it negatively impacts the quality of life of the affected individuals. One commonly used herbal prescription for treating CHHF is Onkyeong-tang (OKT). Although OKT is widely used clinically in treating CHHF, no randomized clinical trial has been performed to evaluate the efficacy and safety of OKT in the treatment of cold hypersensitivity in the feet (CHF). This clinical trial aims to provide objective evidence for the basis of using OKT in the treatment of CHF in Korean women. Methods This trial will be a double-blind, randomized, placebo-controlled, parallel-group, multicenter pilot study. A total of 112 participants will be randomly divided into an OKT treatment group or a placebo group with a 1:1 ratio via a web-based randomization system. The OKT and placebo groups will receive prescribed medications orally three times per day (3 g each time) before or between meals for 8 weeks. The primary outcome studied will be the changes in Visual Analog Scale (VAS) scores of CHF from baseline. Secondary outcomes studied will be the VAS score changes of cold hypersensitivity in the hands, changes in the skin temperature of the hands and feet, total scores of the Korean version of the World Health Organization Quality of Life Scale-abbreviated version, and the results of the cold stress test. Discussion This trial will be the first clinical trial to assess the efficacy and safety of OKT in the treatment of CHF. We anticipate that the findings of the study will provide evidence for the basis of using OKT in treating CHF symptoms and generate basic data for designing a further large-scale randomized clinical trial. Trial registration Clinical Research Information Service (CRIS): KCT0003723. Retrospectively registered on 8 April 2019.