Therapeutic Actions for Muscarinic Antagonists Therapeutic Actions for Muscarinic Antagonists Drug Organ System Application and Comments Atropine, homatropine, tropicamide Eye and Cardiac Causes mydriasis and cycloplegia Used for ophthalmologic exams Can be used for post-MI bradyarrythmias Benztropine CNS Parkinson's disease Scopolamine CNS Motion sickness Fast onset Ipratropium Respiratory Asthma COPD Tiotropium produces a longer bronchodilator effect Relief of rhinorrhea with common cold, allergic and nonallergic rhinitis Oxybutynin, trospium, glycopyrrolate Genitourinary Reduce urgency in mild cystitis Reduce bladder spasms after urologic surgery Methscopolamine, pirenzepine, propantheline Gastrointestinal Peptic ulcer treatment Atropine Muscarinic antagonist blocks effects of cholinesterase inhibitor poisoning Organ system eye: ↑ pupil dilation and cycloplegia lungs: ↓ secretions GI and GU: ↓ stomach acid secretion, ↓ gut motility, and ↓ urgency in cystitis Toxicity CNS: ↑ body temperature, disorientation, hyperthermia in infants cardiovascular: tachycardia and flushing dermatologic: anhidrosis and urticaria GI and GU: dry mouth, constipation, urinary retention ocular: cycloplegia, acute angle-closure glaucoma, dry eyes Atropine adage: "hot as a hare, dry as a bone, red as a beet, blind as a bat, mad as a hatter, the bowel and bladder loser their tone, and the heart runs alone"