1例67岁女性患者为预防动脉硬化性心血管疾病自行口服阿司匹林肠溶片100 mg、3次/d。42 d后出现便血，并进行性加重，导致严重出血性贫血（红细胞计数1.55×10n 12/L、血红蛋白47 g/L）；血压下降至58/33 mmHg（1 mmHg=0.133 kPa）。出血第4天行剖腹探查术，诊断为结肠出血，行肠系膜动脉结扎术后出血停止。患者未经专业医师进行获益和出血风险的评估自行服用阿司匹林，日剂量超过推荐剂量，导致严重下消化道出血，住院手术治疗，属于H级用药错误。n “,”A 67-year-old female patient took aspirin enteric-coated tablets 100 mg thrice daily orally in order to prevent arteriosclerotic cardiovascular disease without doctor′s advice. After 42 days of medication, the patient developed hematochezia, which was progressively aggravated and finally led to severe hemorrhagic anemia (red blood cell count 1.55×10n 12/L, hemoglobin 47 g/L) and decreased blood pressure (58/33 mmHg). On the 4th day of bleeding, exploratory laparotomy was performed and colonic hemorrhage was diagnosed. Ligation of the mesenteric artery was performed and the patient′s bleeding stopped. The patient took aspirin by herself at a daily dose exceeding the recommended dose without assessment of benefits and bleeding risks by professional physicians and developed severe lower gastrointestinal hemorrhage, which led to hospitalization and surgical treatment. It was a grade H medication error.n