CHAPTER 8 DRUGS WITH ANTICHOLINERGIC ACTIONS

Question 1

MOTION SICKNESS DRUGS
- Unknown mechanism in
CNS
- Prevention of motion
sickness and postoperative
nausea and vomiting

Answer 1

Scopolamine

Question 2

GASTROINTESTINAL DISORDERS
- Competitive antagonism
at M3 receptors
- Irritable bowel syndrome,
minor diarrhea

Answer 2

Dicyclomine

Question 3

OPHTHALMOLOGY
- Competitive antagonism
at all M receptors
- Retinal examination;
prevention of synechiae
after surgery

Answer 3

Atropine

Question 4

Shorter duration of action (12–24 h) than atropine

Answer 4

Homatropine:

Question 5

Shorter duration of action (3–6 h)

Answer 5

Cyclopentolate

Question 6

Shortest duration of action (15–60 min)

Answer 6

Tropicamide

Question 7

RESPIRATORY (ASTHMA, COPD)
- Competitive, nonselective
antagonist at M receptors
- Prevention and relief of
acute episodes of
bronchospasm

Answer 7

 Ipratropium

Question 8

URINARY
- Slightly M3-selective
muscarinic antagonist
- Urge incontinence;
postoperative spasms

Answer 8

Oxybutynin

Question 9

CHOLINERGIC POISONING
- Nonselective competitive
antagonist at all
muscarinic receptors in
CNS and periphery
- Mandatory antidote for
severe cholinesterase
inhibitor poisoning

Answer 9

Atropine

Question 10

CHOLINERGIC POISONING
- Very high affinity for
phosphorus atom but
does not enter CNS
- Usual antidote for early
stage (48 h) cholinesterase
inhibitor poisoning

Answer 10

Pralidoxime