B - 4. Muscarinic receptor blocking drugs

Question 1

Muscarinic receptor antagonists mechanism

Answer 1

Blocking of muscarinic receptors -> removes parasympathetic stimulation on effector cells -> sympathetic dominance

Question 2

TERTIARY TROPEINS: Names

Answer 2

Contains tertiary amines -> lipid soluble

Atropine
Scopolamine

Question 3

Atropine indications

Answer 3

antispasmodic
antisecretory
management of AChE inhibitor overdose
antidiarrheal

Question 4

Atropine length of action and metabolism

Answer 4

24-36 h

not metabolized; excreted through kidneys

Question 5

Atropine SE

Answer 5

Hyperthermia (sweat glands are not stimulated) -> atropine fever
Bronchodialation
Tachycardia, can become VFIB
Urinary retention (constricts sphincters)

Question 6

Three C’s of atropine (and other muscarinic antagonists)

Answer 6

Cardiotoxicity
Convulsions
Coma

Question 7

Scopolamine

Answer 7

Used in motion sickness

- Auditory nerve is primarily an ACh nerve -> all efferents from semi-circular canal to vomiting center are muscarinic

Question 8

QUATERNARY TROPEINS names

Answer 8

Quarternary amines -> water soluble

Ipratropium
Thiotropium

Question 9

QUATERNARY TROPEINS indication

Answer 9

COPD, asthma -> inhibits bronchospasms

Thiotropium is M3 selective -> does not act on M2 (no inhibitory effects on heart)

Question 10

SYNTHETIC DRUGS with tertiary N names

Answer 10

procyclidine
solifenacine
cyclopentolate

Question 11

oxybutinine

Answer 11

Anticholinergic used for treating overactive bladder

Question 12

Common side effects of anticholinergics

Answer 12

dry mouth
blurry vision
constipation
drowsiness
sedation
hallucinations
memory problems
trouble urinating