Scopolamine is a tropane alkaloid drug with muscarinic antagonist effects. It is among the secondary metabolites of plants from Solanaceae (nightshade) family of plants. Scopolamine exerts its effects by acting as a competitive antagonist at muscarinic acetylcholine receptors, specifically M1 receptors; it is thus classified as an anticholinergic, antimuscarinic drug. Its use in medicine is relatively limited, with its chief uses being in the treatment of motion sickness and postoperative nausea and vomiting. Scopolamine can be administered orally, subcutaneously, ophthalmically and intravenously, as well as via a transdermal patch. The transdermal patch for prevention of nausea and motion sickness employs scopolamine base, and is effective for up to three days. The oral, ophthalmic, and intravenous forms have shorter half-lives and are usually found in the form scopolamine hydrobromide.