Scopolamine pharmacological properties

Pharmacological Properties The Prototypical Alkaloids Atropine and Scopolamine... 

Many pharmacologically active organic chemicals fonnd in natnre are alkaloids. In general, these componnds contain one or more nitrogen atoms, which in turn impart some basicity to the molecnle. Well-known alkaloid examples are caffeine, cocaine, codeine, ephedrine, morphine, nicotine, qninine, and scopolamine. Heroin is derived from morphine by a chemical modification that increases lipophilicity, making the heroin molecnle inherently more pharmacologically potent than morphine. The exhibition of its basic properties by an alkaloid (Aik) involves (by definition) the acceptance of a proton H+ according to ... 

Belladonna alkaloids have an extremely broad pharmacological spectrum. In addition to their ability to block M-receptors, atropine and scopolamine also act on other receptors, thus showing corresponding effects. They can only block nicotinic cholinergic receptors, however, in significantly larger doses than those used in clinics. Atropine also exhibits properties of local anesthetics and histamine (Hj) receptor blockers. Atropine and... 

Motion sickness. Effective prophylaxis can be achieved with the parasympatholytic scopolamine (p.110) and Hq-antihistaminics (p.118) of the diphenylmethane type (e.g., diphenhydramine, meclizine). Antiemetic activity is not a property shared by all para-sympatholytics or antihistaminics. The ef -cacy of the drugs mentioned depends on the actual situation of the individual (gastric filling, ethanol consumption), environmental conditions (e.g., the behavior of fellow trav-Luellmann, Color Atlas of Pharmacology All rights reserved. Usage subject to terms... 

These medicinal plants are now understood to owe their pharmacological and toxicological properties to several extremely potent alkaloids (Fig. 8-13). The first to be isolated in 1831 was atropine. Other solanaceous alkaloids are atroscine (which like atropine is racemic), hyoscyamine and scopolamine, and the levorotatory enantiomers of racemic atropine and atroscine, respectively. 

The ability to dry up bronchial secretions and reduce laryngospasms (induced by some general anesthetics) has been the reason for using atropine and scopolamine as presurgical medication. It should be mentioned that scopolamine, which differs from atropine by the (3-6,7-epoxy bridge (Fig. 8-13), while it generally parallels atropine s pharmacological spectrum, does not share its cerebral and medullary stimulation rather it exhibits CNS depression and amnesia, properties applied to anesthesia in an adjunct capacity. 

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