东莨菪碱（法语、英语：Scopolamine，德语：Scopolamin)，又称左旋-天仙子胺），是一种莨菪烷生物碱药物，具有毒蕈碱受体拮抗剂作用。东莨菪碱通过在毒蕈碱乙酰胆碱受体，充当竞争性拮抗剂发挥其效用；因而它被分类为抗胆碱药物、抗毒蕈碱药物。是与毒蕈碱受体抗化剂作用下人工制造的莨菪烷类生物碱的药物。药品主要来源来自茄科植物天仙子、曼陀罗等。

该药品虽然剧毒，甚至曾被用作犯罪；甚至有「魔鬼的呼吸」别称，但事实上，因其作为乙酰胆碱抑制剂的性质，在非常小剂量施作上，可作为合法医疗应用；例如治疗晕车的耳后贴剂、手术后的恶心、肠易激综合征、胃肠痉挛、肾或胆道痉挛以及手术前给药以减少呼吸道分泌物。

Hyoscine hydrobromide, also known as scopolamine hydrobromide, is a medication used in the treatment of motion sickness and postoperative nausea and vomiting.

One common side effect is drowsiness. Scopolamine is a tropane alkaloid drug with muscarinic antagonist effects. Hyoscine hydrobromide exerts its effects by acting as a competitive antagonist at muscarinic acetylcholine receptors; it is thus classified as an anticholinergic, antimuscarinic drug. Although it is usually referred to as a nonspecific antagonist, there is indirect evidence for m1-receptor subtype specificity.