Unit 4: Cholinergic Antagonists

Question 1

All cholinergic antagonists COMPETE with ______ to bind @ the _______ ________

Answer 1

ACETYLCHOLINE

MUSCARINIC RECEPTOR

Question 2

Side effects of CHOLINERGIC ANTAGONISTS on the EYE

Answer 2

mydriasis (excessive dilation), cycloplegia (blurred vision)

Question 3

Side effects of CHOLINERGIC ANTAGONISTS on the SKIN

Answer 3

decreased sweating, flushing

Question 4

Side effects of CHOLINERGIC ANTAGONISTS on the GI TRACT

Answer 4

decreased motility

Question 5

Side effects of CHOLINERGIC ANTAGONISTS on the HEART

Answer 5

increase in heart rate with high doses

Question 6

Side effects of CHOLINERGIC ANTAGONISTS on the RESPIRATORY SYSTEM

Answer 6

bronchial dilation, decreased secretions

Question 7

Side effects of CHOLINERGIC ANTAGONISTS on the GU SYSTEM

Answer 7

urinary retention

Question 8

Side effects of CHOLINERGIC ANTAGONISTS on the CNS

Answer 8

drowsiness, hallucinations, coma

Question 9

3 types of cholinergic antagonists

Answer 9

1. muscarinic antagonists
2. ganglionic blockers
3. neuromuscular blockers

Question 10

What do the competitive neuromuscular blockers do?

Answer 10

relax skeletal muscles

Question 11

ALL neuromuscular blockers bind to ALL ________ receptors, and some __________ receptors

Answer 11

nicotinic

muscarinic

Question 12

List the 2 classifications of neuromuscular blockers

Answer 12

1. depolarizing blockers

2. nondepolarizing blockers

Question 13

What is the difference between depolarizing blockers and nondepolarizing blockers?

Answer 13

DEPOLARIZING blockers bind to receptor and OPEN THE ION CHANNEL and result in depolarization; nondepolarizing blockers bind but DO NOT OPEN THE ION CHANNEL

Question 14

How can we reverse the neuromuscular blockers? Why?

Answer 14

with a cholinesterase inhibitor, as it increases the presence of acetylcholine that competes with the receptor blocker

Question 15

What is often co-administered with a cholinesterase inhibitor to reverse a neuromuscular blocker?

Answer 15

a muscarinic antagonist

REMEMBER: neuromuscular blockers affect ALL nicotinic receptors and some muscarinic; we want to reverse the blocker by increasing acetylcholine–but we only want to affect the nicotinic receptors; an increase in acetylcholine everywhere will also affect muscarinic receptors–so we want to oppose that with a muscarinic antagonist

Question 16

Name a medication that can be administered with a cholinesterase inhibitor, and describe how it works

Answer 16

Sugamadex: it forms complexes with rocuronium or vecuronium (nondepolarizing blockers), which prevents them from binding to nicotinic receptors

Question 17

Name a depolarizing neuromuscular blocker

Answer 17

SUCCINYLCHOLINE

Question 18

What is a potentially FATAL adverse effect of the neuromuscular blocker succinylcholine?

Answer 18

malignant hyperthermia

Question 19

What is used to treat malignant hyperthermia?

Answer 19

DANTROLENE

Question 20

How does Dantrolene work?

Answer 20

it interferes with the release of calcium from the sarcoplasmic reticulum in the skeletal muscle

Question 21

Aside from neuromuscular blockers, how else can the neuromuscular junction be blocked? (HINT: how is the neuromuscular junction stimulated?)

Answer 21

by drugs that block the release of acetylcholine

Question 22

Name a drug that blocks the release of acetylcholine at ALL cholinergic synapses

Answer 22

Botulinum toxin

Question 23

What is Botulinum toxin used to treat?

Answer 23

muscle spasms, excessive sweating, wrinkles