Cholinergic Drugs II

Question 1

inhalation drugs for tx of COPD (and asthma)

Answer 1

ipratropium and tiotropium (muscarinic antagonist)

Question 2

used to produce mydriasis with cycloplegia (paralysis of the ciliary muscle of the eye leading to loss of accommodation so can’t see near)

Answer 2

homatropine, cyclopentolate, tropicamide

muscarinic antagonist

Question 3

muscarinic antagonist that is used to treat parkinsonism and the extrapyrimidal effects of antipsychotic drugs

Answer 3

benztropine and trihexphenidyl

Question 4

muscarinic antagonist used orally to inhibit GI motility

Answer 4

glycopyrrolate

Question 5

muscarinic antagonist used to treat overactive bladder

Answer 5

tolterodine

Question 6

what happens to the heart when antimuscarinic drugs are used at different levels

Answer 6

at low to medium levels can cause bradycardia and sedation

at high levels can cause tachycardia

Question 7

who are most at risk for anticholinergic drugs

Answer 7

elderly especially those with cognitive impairment because they already do not produce enough acetylcholine and hence blocking the little they have can cause some serious damage

Question 8

what are the nicotine receptor antagonists

Answer 8

mecamylamine, trimethaphan, and hexamethonium

ganglion blockers

Question 9

what were the ganglion blockers used to treat (name them again)

Answer 9

mecamylamine, trimethaphan, hexamethonium

used to tx hypertension but have been replaced

Question 10

effects of ganglion blockers on the following: arterioles, veins, heart, iris, ciliary muscle, GI tract, urinary bladder, salivary glands, sweat glands

helps to know what system dominates in each

Answer 10

arterioles - vasodilation so low BP
veins - dilation so decreased cardiac output
heart - increase HR aka tachycardia
iris - mydriasis
ciliary muscle - cycloplegia (focus for far vision)
urinary bladder - urinary retention
salivary glands - xerostomia (dry mouth)
sweat gland - anhydrosis

Question 11

non depolarizing (competitive) neuromuscular blocker drug

Answer 11

tubocurarine
nondepolarizing in that it binds to the nicotinic receptor inhibiting acetylcholine from binding hence stopping depolarization

Question 12

use of tubocurarine

Answer 12

anesthetic during surgery to relax skeletal muscle

Question 13

how can you overcome effect of tubocurarine

Answer 13

give acetylcholinesterase inhibitor neostigmine or edrophonium

Question 14

adverse effect of tubocurarine

Answer 14

some (so basically not tubocurarine) are moderate blockers of muscarine receptors

histamine release (for tubocurarine)

Question 15

depolarizing neuromuscular junction blocker

Answer 15

succinylcholine

Question 16

how does succinylcholine work

Answer 16

it binds to nicotinic receptor causing depolarization but it does not get metabolized so membrane remains depolarized and unresponsive to additional impulses leading to flaccid paralysis

Question 17

when is succinylcholine used

Answer 17

rapid endotracheal intubation (rapid onset and brief duration so effective for this)
ECT (electroconvulsive therapy)

Question 18

adverse effect of succinylcholine

Answer 18

malignant hyperthermia

Question 19

what do you treat malignant hyperthermia with

Answer 19

dantrolene

Question 20

drugs that act presynaptically

Answer 20

hemicholium 3, vesamicol, botulinum toxin

Question 21

how does hemicholium work

Answer 21

it inhibits the synthesis of acetylcholine by blocking the high affinity transporter for choline hence preventing uptake of choline

for research only

Question 22

how does vesamicol work

Answer 22

inhibits acetycholine storage

blocks ACh-H transporter that is used to store ACh in the vesicle

Question 23

how does botulinum toxin work

Answer 23

it inhibits acetylcholine release

Question 24

what is botulinum used for

Answer 24

diseases associated with increased muscle tone like achalasia, strabismus, blepharospasm, focal dystonia

also used to facial wrinkles