114-49-8

Description

Scopolamine is a tropane alkaloid that can be found in many plants of the Solanaceae (nightshade) family. It is a muscarinic receptor antagonist that can be used to induce memory impairment in animals. Scopolamine prevents motion sickness, nausea, and vomiting in animals.

Chemical Properties

Off-White Solid

Uses

An acetylcholine antagonist. Used in treatment of motion sickness; antiemetic; antispasmodic; mydriatic; preanesthetic medicant

Definition

ChEBI: A hydrobromide that is obtained by reaction of scopolamine with hydrogen bromide.

Brand name

Isopto Hyoscine (Alcon); Transderm-Scop (Ciba-Geigy).

General Description

Scopolamine hydrobromide(hyoscine hydrobromide) occurs as white orcolorless crystals or as a white, granular powder. It is odorlessand tends to effloresce in dry air. It is freely soluble inwater (1:1.5), soluble in alcohol (1:20), only slightly solublein chloroform, and insoluble in ether.Scopolamine is a competitive blocking agent of theparasympathetic nervous system as is atropine, but it differsmarkedly from atropine in its action on the higher nervecenters. Both drugs readily cross the blood-brain barrierand, even at therapeutic doses, cause confusion, particularlyin the elderly.

Air & Water Reactions

Sensitive to air, light and moisture. Water soluble.

Reactivity Profile

Scopolamine hydrobromide is incompatible with acids, bases and oxidizing agents. .

Fire Hazard

Flash point data for Scopolamine hydrobromide are not available; however, Scopolamine hydrobromide is probably combustible.

Biological Activity

Non-selective muscarinic antagonist. Widely used clinically to treat motion sickness.

Clinical Use

A sufficiently large dose of scopolamine will cause an individualto sink into a restful, dreamless sleep for about8 hours, followed by a period of approximately the samelength in which the patient is in a semiconscious state.During this time, the patient does not remember events thattake place. When scopolamine is administered with morphine,this temporary amnesia is termed twilight sleep.

Drug interactions

Potentially hazardous interactions with other drugs None known

Metabolism

Hyoscine hydrobromide is almost entirely metabolised, probably in the liver; only a small proportion of an oral dose is excreted unchanged in the urine. In one study in man, 3.4% of a single dose, administered by subcutaneous injection was excreted unchanged in urine within 72 hours.

Purification Methods

The hydrobromide is recrystallised from Me2CO, H2O or EtOH/Et2O and dried. It is soluble in H2O (60%) and EtOH (5%) but insoluble in Et2O and slightly in CHCl3. The hydrochloride has m 300o (from Me2CO). The free base is a viscous liquid which forms a crystalline hydrate with m 59o and [] D 20 -28o (c 2.7, H2O). It hydrolyses in dilute acid or base. [Meinwald J Chem Soc 712 1953, Fodor Tetrahedron 1 86 1957, Beilstein 6 III 4185.]