The Efficacy Evaluation of Danggui Buxue Tang (DBT) on Menopausal Symptoms: Clinical Trial Protocol Design and Considerations

Abstract

Background: Almost two third women experience hot flushes after menopause. Conventional treatment is the use of oestrogen replacement therapy or hormone replacement therapy (HRT). Although HRT is considered the most effective treatment for hot flushes, it may increase the risk of breast cancer and thromboembolic disease. Danggui Buxue Tang (DBT) is a combination of Danggui A§Â•Â¶A¦Â­Â¸ (Radix Angelicae Sinensis) and Huangqi A©Â»ÂƒA¨ÂSÂa (Radix Astragali), which has been reported in ancient Chinese medicinal literature to relieve blood deficiency in female. The aims of the clinical studies were to proof the efficacy and to find out the optimal dose of DBT for menopausal symptoms. Methods/Design: The clinical studies were consisted of two stages. Stage I was designed as a single-center, randomized, double blind, placebo-controlled parallel study. Eligible subjects were randomized to one of two groups: DBT or placebo. Stage II was designed as a multiple-dose escalation clinical trial to look for the optimum dose for menopausal women. Eligible subjects were randomized to one of three dosage groups: low, middle and high dose. Results: Through the well-designed and well-conducted clinical trials, we found that in stage I trial, in analysis by severity of flushes, there was a significant reduction in the number of mild hot flushes in DBT group but not in the placebo group. In stage II trial, there were significant reduction in hot flushes and night sweats in high and middle dose groups after 3 months treatment, however, no significant changes were seen in low dose group. Conclusion: Our experiences suggested that it was feasible to perform a well-designed TCM clinical trial although there were challenges had to deal with, such as placebo preparation, outcome/endpoints determination and batch-to-batch consistency of the study medication.