Exam 2 - Cholinomimetics and Antimuscarinics

Question 1

1. List the major clinical uses of cholinomimetic agonists

Answer 1

Used for glaucoma, post-operative ileus, urinary retention, myasthenia gravis, and to diagnose bronchial hyperreactivity (methacholine challenge

Question 2

2. Describe the pharmacodynamic differences between direct-acting and indirect acting cholinomimetic agents and give examples of each.

Answer 2

Direct-acting: Bind directly to cholinergic receptors (e.g., ACh, pilocarpine).

Indirect-acting: Inhibit acetylcholinesterase, increasing ACh (e.g., neostigmine, edrophonium)

Question 3

3. Describe the differences between a nicotinic and cholinergic receptor.

Answer 3

Nicotinic: Ion channels, fast response, found in ganglia and neuromuscular junctions.

Muscarinic: G-protein-coupled, slower, found in parasympathetic target organs​

Question 4

4. List the effects of cholinomimetics in the major organ systems.

Answer 4

Eye: Miosis, increased aqueous drainage.

Cardiovascular: Bradycardia, vasodilation.

Respiratory: Bronchoconstriction.

GI: Increased peristalsis.

GU: Increased bladder tone

Question 5

5. Define the different types of glaucoma and the use of cholinomimetics.

Answer 5

Open-angle: ACh agonists increase aqueous outflow.

Angle-closure: Used as emergency treatment​

Question 6

6. List the major signs and symptoms of (1) organophosphate insecticide poisoning and (2) acute nicotine toxicity.

Answer 6

Organophosphates: SLUDGE-M symptoms (salivation, lacrimation, urination, defecation, GI, emesis, miosis.), bradycardia, bronchospasm

Nicotine: Vomiting, CNS excitement, respiratory paralysis​

Question 6

7. Describe the function of acetylcholinesterase, drug targets, and organophosphate aging.

Answer 6

AChE breaks down ACh into acetate and choline. Organophosphates inhibit AChE, causing irreversible binding (aging) without treatment like pralidoxime​

Question 7

10. Recall the use of cholinomimetics in diseases such as myasthenia gravis, glaucoma, and post-operative ileus.

Answer 7

Myasthenia Gravis: AChE inhibitors like neostigmine improve neuromuscular transmission.

Glaucoma: Pilocarpine increases outflow of aqueous humor.

Ileus: Bethanechol stimulates GI motility

Question 7

8. Describe the effects of atropine on the major organ systems.

Answer 7

Causes mydriasis, tachycardia, decreased GI motility, reduced salivation, bronchodilation

Question 8

9. List the signs, symptoms, and treatment of atropine overdose.

Answer 8

Symptoms: Hyperthermia, dry mouth, hallucinations, blurred vision.

Treatment: Supportive care, physostigmine​

Question 9

12. Describe the effects of the two different types of nicotinic antagonists.

Answer 9

Ganglion Blockers: Cause widespread effects due to blocking both sympathetic and parasympathetic ganglia.

Neuromuscular Blockers: Cause paralysis by blocking skeletal muscle contraction

Question 10

11. List the major clinical indications and contraindications for the use of muscarinic antagonists such as atropine.

Answer 10

Indications: Bradycardia, pre-anesthesia, ophthalmic exams.

Contraindications: Glaucoma, urinary retention​

Question 11

13. Name the two categories of muscle relaxants.

Answer 11

Depolarizing: Succinylcholine.
Non-depolarizing: Pancuronium, vecuronium

Question 12

14. Differentiate depolarizing and non-depolarizing muscle relaxants, and give examples of each.

Answer 12

Depolarizing: Cause persistent depolarization (e.g., succinylcholine).
Non-depolarizing: Compete with ACh at the receptor (e.g., pancuronium)​(