让健康受试者分别或同时口服咖啡因和乙酰水杨酸，考察受试者对痛刺激的反应并测定受刺激部位血流量的变化和血药浓度，实验证明，咖啡因对乙酰水杨酸的镇痛作用无明显协同效应。 Caffeine and acetylsalicylic acid were orally administered to healthy subjects, the response of the subject to pain stimuli was measured, and the change of blood flow and the plasma concentration of the stimulated site were measured. The results showed that caffeine could effectively inhibit acetylsalicylic acid The analgesic effect no significant synergistic effect.