The Effect of Caffeine on Acupuncture Analgesia With the Human Pain Model

Inclusion Criteria: * Age of a subject is between 18 and 40 years old, male or female * No known active ongoing disease, in good general health, with a BMI ranging from 18 to 30 kg/m2 * No history of mental disorders,infectious diseases and bleeding disorders. No history of allergic reaction. Females who are not pregnant, lactating, of child-bearing potential, or have no a pregnancy plan within 3 months * No smoking, drinking alcohol * No intake of beverage, food and alcohol ,which contains caffeine at least two hours * No use of any of the methyl purine drugs. No use of any of the drugs ,which can affect the half-life of caffeine, such as: cimetidine, steroids, growth hormone, etc * No previous experience with acupuncture or other related treatments within 3 days * Reliable, cooperative, and of adequate intelligence to record the requested information on the questionnaire form * Informed consent form must be signed by subjects Exclusion Criteria: * Subject with serious blood, heart, liver, kidney disease, digestive, or hematopoietic system disease * Subject with serious mental disorders, infectious diseases and bleeding disorders. Subject has a history of allergic reaction. Females who are pregnant, lactating, of child-bearing potential, or have a pregnancy plan within 3 months; * Prior use of any type of analgesic drugs before study within 5 half-lives of the drugs * Use of any of the methyl purine drugs. Use of any of the drugs, which can affect the half-life of caffeine, such as: Sympathomimetic drugs, theophylline drugs , α or β-blockers drugs, and any antihypertensive drugs, etc * Ingestion of any caffeine-containing beverage, food or alcohol 6 hours or less before study * Subject has a previous experience with acupuncture or other related treatments within 7 days * Suffered from medical or psychiatric disorders that prevented them from participating in the study * Subject who belongs to acupuncture-phobia