Randomization and blinding
All participants were randomly assigned to anisodamine group (bilateral ST36 acupoint injection with anisodamine) or control group (bilateral ST36 injection with normal saline) in a 2:1 ratio. The randomization was computer-generated by using The allocation sequence was concealed until the end of data collection, and the drug or placebo was prepared by the independent researcher thus maintaining blinding of the patients, acupuncturist, outcome assessors.