†These authors contributed equally.
Background: Primary dysmenorrhea (PD) afflicts many childbearing-age
women, with a high prevalence ranging from 17% to 90%. The Dingkun pill (DKP),
a traditional Chinese medicine formula, has been prescribed for managing
menstrual disorders empirically in clinical practice for a long time, but there
are very few high-quality studies supporting this practice. Therefore, this trial
aimed to assess the efficacy and safety of DKP in patients with PD.
Methods: Our study was a multicenter, prospective, randomized,
double-blind, placebo-controlled study. DKP or placebo was prescribed to
participants from the 5th to 14th day of each menstrual cycle for 12 weeks.
Changes in pain intensity were measured by a visual analog scale (VAS) and were
compared between groups using repeated measures analysis. The pain mediators and
sex hormones were also assessed before and after the treatment, and their
intergroup changes from the baseline were analysed by student t-test.
The hemodynamic indices and safety profile of DKP were also investigated.
Results: A total of 156 women were recruited and randomly allocated to
receive either DKP or placebo, of whom 142 (73 in DKP and 69 in sham control)
completed the study. A more distinctive reduction in VAS scores was observed in
the DKP group, compared with placebo (–2.68