西咪替丁、雷尼替丁、法莫替丁和尼扎替丁等H_2受体拮抗剂能有效地治疗胃、十二指肠溃疡以及返流性食管炎。1989年3月,丹麦允许西咪替丁、雷尼替丁作为非处方药物应用,这一决定引起了国际广泛关注,并相继对这类药物非处方应用后对人们身体健康的影响进行调查。本文对H_2受体拮抗剂非处方应用的安全性问题进行了探讨。临床观察表明,服用西咪替丁的患者与接受安慰剂的患者相比,副作用无显著差别。售后观察表明,上万例患者使用几年后均未出现 H 2 receptor antagonists such as cimetidine, ranitidine, famotidine and nizatidine are effective in the treatment of gastric and duodenal ulcers and reflux esophagitis. In March 1989, Denmark allowed cimetidine and ranitidine to be used as over-the-counter medicines. This decision attracted widespread international attention and investigated the impact on people’s health after over-the-counter use of such drugs. This article discusses the safety of over-the-counter H 2 receptor antagonists. Clinical observations show no significant differences in side effects between patients taking cimetidine and those receiving placebo. Aftermarket observation shows that tens of thousands of patients did not appear after using a few years