How is scopolamine as antimuscarinic?

Tertiary amine belladonna alkaloid, produces peripheral effects like atropine, greater action on CNS (observed at therapeutic doses). Actions (anti-motion sickness, unusual blocking of short-term memory, produces sedation but at higher doses excitation, may produce euphoria) Therapeutic uses (limited prevention of motion sickness, blocking short term memory, prophylactic effect not treating of motion sickness, amnestic action important adjunct drug in anesthetic products)