Adverse drug reactions of Yunnan Baiyao capsule: a multi-center intensive monitoring study in China.

Background: Yunnan Baiyao capsule (YBC), a marketed herbal medicine in mainland China, is widely used to control bleeding. This study's aim was to determine the occurrence of YBC-related adverse drug reactions (ADRs) among users of the medicine. Methods: This hospital-intensive monitoring study was conducted in 163 hospitals across China. Consumers who used YBC (Z53020799) between June 2015 and December 2016 were included. By face-to-face interview or telephone, the circumstances and experiences of their adverse events (AEs), during drug taking and 14 days after drug withdrawal, were recorded at follow-up and later encoded by International Conference on Harmonisation (ICH) 1997. The Naranjo Adverse Reaction Probability Scale (APS) was used to determine the likelihood of ADRs. Results: A total of 31,556 participants were included (follow-up rate 99.40%). AEs occurred in 742 participants, of which 561 were reported as "not related with drug use" by their physician-in-charge. Based on the remaining 181 cases, the overall ADR incidence was 1.17% (intention to treat) and 0.58% (per protocol), with abnormal findings mainly concentrated in the digestive system, skin and respiratory system. The top 5 frequently reported reactions were nausea and vomiting (0.1785%, 56 cases of 31,367 participants), functional diarrhea (0.1180%, 37 of 31,367 participants), stomach discomfort (0.0893%, 28 of 31,367 participants), rash (0.0574%, 18 of 31,367 participants) and gastro-esophageal reflux (0.0383%, 12 of 31,367 participants). Among them, functional diarrhea and stomach discomfort were judged as definite ADRs of YBC. Conclusions: In this large study, treatment of YBC was found to be associated with ADRs with an incidence of 1.17%, although most were relatively mild and not considered to be life-threatening.