Muscarinic antagonist. Used to treat bradycardia and for ophthalmic applications.

Eye: ↑ pupil dilation, cycloplegiaAirway: Bronchodilation, ↓ secretionsStomach: ↓ acid secretionGut: ↓ motilityBladder: ↓ urgency in cystitis

Adverse effects: ↑ body temperature (due to ↓ sweating); rapid pulse; dry mouth; dry, flushed skin; cycloplegia; constipation; disorientationCan cause acute angle-closure glaucoma in elderly (due to mydriasis), urinary retention in men with prostatic hyperplasia, and hyperthermia in infants.

- Jimson weed (Datura) → gardener's pupil (mydriasis due to plant alkaloids)