Herbal medicine (Taohong Siwu Tang) for the treatment of primary dysmenorrhea: A systematic review and meta-analysis

Objectives: This systematic review aimed to evaluate the efficacy and safety of Tao-Hong Siwu Tang (TST) for the treatment of primary dysmenorrhea. Methods: We searched four English databases (MEDLINE, EMBASE, Allied and Complementary Medicine Database, and Cochrane Central Register of Controlled Trials [CENTRAL, Cochrane Library]), three Chinese databases (China National Knowledge Infrastructure, Wanfang, and Chinese Science and Technology Periodical Database), two Korean databases (Oriental Medicine Advanced Searching Integrated System and Korean traditional Knowledge Portal), and one Japanese database (Citation Information by NII). All randomized controlled trials (RCTs) using TST or modified TST (MTST) were included. Three independent reviewers extracted the data, assessed the risk of bias according to the Cochrane criteria, and performed a meta-analysis. Results: A total of 85 possibly relevant articles were identified, and five trials met our inclusion criteria. The meta-analysis showed a favorable effect of MTST compared to non-steroidal anti-inflammatory drugs (NSAIDs) (n = 486, risk ratio [RR] =1.53, 95% confidence interval [95% CI] =1.37-1.72, I-2 = 39%). Among the included trials, one RCT showed superior effects of MTST on primary dysmenorrhea recurrence rate compared to NSAIDs (n = 246, RR = 0.31, 95% CI = 0.15-0.63, P= 0.001). Another RCT revealed a beneficial impact of oral contraceptives (OCs) used in combination with TST compared to OCs alone (n = 60, RR= 1.35, 95% CI = 1.02-1.79, P= 0.04). Conclusion: This systematic review and meta-analysis provides moderate quality evidence for the superiority of MTST over NSAIDs as well as that of TST plus OCs over OCs in the treatment of primary dysmenorrhea. (C) 2020 Published by Elsevier Inc.