Scopolamine [skoe-POL-a-meen], another tertiary amine belladonna alkaloid, produces peripheral effects similar to those of atropine. However, scopolamine has greater action on the CNS (unlike with atropine, CNS effects are observed at therapeutic doses) and a longer duration of action in comparison to those of atropine. It has some special actions as indicated below.
1. Actions: Scopolamine is one of the most effective anti–motion sickness drugs available
Figure : Scopolamine is an effective antimotion sickness agent.
Scopolamine also has the unusual effect of blocking short-term memory. In contrast to atropine, scopolamine produces sedation, but at higher doses it can produce excitement instead. Scopolamine may produce euphoria and is subject to abuse.
2. Therapeutic uses: Although similar to atropine, therapeutic use of scopolamine is limited to prevention of motion sickness (for which it is particularly effective) and to blocking short-term memory. [Note: As with all such drugs used for motion sickness, it is much more effective prophylactically than for treating motion sickness once it occurs. The amnesic action of scopolamine makes it an important adjunct drug in anesthetic procedures.]
3. Pharmacokinetics and adverse effects: These aspects are similar to those of atropine.