How is atropine as antimuscarinic drug?

Tertiary amine belladonna alkaloid, high affinity for muscarinic receptors binds competitively prevents acetylcholine from binding. Acts centrally or peripherally, action for 4 hours except when topic on eye may last for days Action on eye (persistent mydriasis, unresponsiveness to light, cycloplegia (cannot focus on near vision), in patients with narrow angle glaucoma can lead to increase in intraocular pressure dangerous. On GI (antispasmodic reduce activity of GI, no effect of HCl production, not effective for healing of peptic ulcer) On Urinary (reduce hypermotility of bladder, used in enuresis among children but a adrenergics better use) On CV (Block M2 receptors on SA node cause increase in cardiac rate, don't affect BP) On secretions (block salivary glands, dries mucosa (xerostomia), sweat and lacrimal glands also affected) Ophthalmo (mydriatic and cycloplegic effects, replaced by short acting antimuscarinics) Antispasmodic (relaxes GI and bladder) Antidote of cholinergic agonists (treats overdoses of cholinesterase inhibitors and mushroom poisoning( Antisecretory (prior to surgery stop respiratory secretions