Pharm - Autonomic Drugs (Muscarinic Antagonists)

Question 1

What 3 muscarinic antagonists affect the eye? What are their 2 clinical applications?

Answer 1

(1) Atropine, (2) Homatroprine, (3) Tropicamide; (1) Mydriasis (2) Cyclopegia

Question 2

What 2 muscarinic antagonists affect the CNS? What is the clinical application of each?

Answer 2

(1) Benzotropine, (2) Scopolamine; BENZOTROPINE - Parkinson’s disease (Think: “Park my Benz”); SCOPOLAMINE - Motion sickness (relief from CNS effects of M1)

Question 3

What 2 muscarinic antagonists affect only the respiratory system? What are their applications?

Answer 3

)1) Ipratropium, (2) tiotropium; (1) COPD (2) Asthma; Think: “I pray I breathe soon!”

Question 4

What 6 muscarinic antagonists affect the genitourinary system? What are its applications?

Answer 4

(1) Oxybutynin (2) Darifenacin (3) Solifenacin; Other agents: (4) Tolterodine, (5) Festerodine, (6) Trospium; (1) Reduce urgency in mild cystitis (2) Reduce bladder spasms

Question 5

What muscarinic antagonist affects both the gastrointestinal and respiratory systems? What are its clinical applications (give based on route of administration)?

Answer 5

Glycopyrrolate; (1) Parenteral: Postoperative use to reduce airway secretions (2) Oral: drooling & Peptic ulcer

Question 6

What kind of drug is atropine? What are its 2 major clinical uses?

Answer 6

Muscarinic antagonist; Used to treat brachycardia and for ophthalmic applications

Question 7

What are 5 organ systems acted on by atropine? In what way is each impacted?

Answer 7

(1) Eye - increase pupil dilation, cyclopegia (2) Airway - decrease secretions (3) Stomach - decrease acid secretion (4) Gut - decrease motility (5) Bladder - decrease urgency in cystitis

Question 8

What symptoms of Cholinesterase inhibitor poisoning can Atropine block versus not block, and why?

Answer 8

Blocks Diarrhea, Urination, Miosis, Brochospasm, Bradycardia, Lacrimation, Sweating, and Salivation (all mediated by Muscarinic receptor) (Think: DUMBBeLSS”); Does NOT block Skeletal muscle and CNS excitation, which is mediated by nicotinic receptors.

Question 9

What are 7 signs of Atropine (antimuscarinic) toxicity?

Answer 9

(1) Increased body temperature (due to decreased sweating) (2) Rapid pulse (3) Dry mouth (4) Dry, flushed skin (5) Cycloplegia (6) Constipation (7) Disorientation; Think: “HOT as a hare, DRY as a bone, RED as a beet, BLIND as a bat, MAD as a hatter”

Question 10

What can Atropine cause in the following patient populations: (1) elderly (2) men (3) infants?

Answer 10

Can cause (1) acute angle-closure glaucoma in elderly (due to mydriasis), (2) urinary retention in men with prostatic hyperplasia, and (3) hyperthermia in infants

Question 11

What is the genus of Jimson weed? What clinical effect can it have, and why?

Answer 11

Jimsom weed (Datura) => gardeners pupil (mydriasis due to plant alkaloids)