Atropine

Question 1

What is the mechanism of action of atropine?

Answer 1

Muscarinic acetylcholine antagonist that blocks vagal input to SA and AV nodes

Question 2

How does atropine counteract bradycardia?

Answer 2

By increasing cardiac conduction

Question 3

What effect can atropine have on the AV block?

Answer 3

It can reverse AV block and restore normal sinus rhythm

Question 4

How long is the effect of atropine?

Answer 4

Short-lived

Question 5

Why is the effect of atropine short lived?

Answer 5

Due to short half life

Question 6

What are the routes of delivery of atropine?

Answer 6

PO
IV
IM

Question 7

Who should administer IV atropine?

Answer 7

Only those trained in its use

Question 8

What are the indications for the use of atropine?

Answer 8

• Bradycardia
• Organophosphorus poisoning
• GI smooth muscle spasm

Question 9

What dose of atropine is used for bradycardia following beta-blocker overdose?

Answer 9

3mg IV

Question 10

What does of atropine is used for intra-operative bradycardia?

Answer 10

300-600mcg IV, larger in emergency

Question 11

What dose of atropine is used for bradycardia following MI?

Answer 11

500mcg IV

Question 12

When is atropine contraindicated?

Answer 12

• Myasthenia gravis
• Narrow-angle glaucoma
• Pyloric stenosis
• Prostatic hypertrophy

Question 13

Who should atropine be avoided in?

Answer 13

• Children
• Elderly
• Down syndrome

Question 14

Who should atropine be used with caution in?

Answer 14

• Cardiovascular disease
• Arrhythmias
• Autonomic neuropathy
• Individuals susceptible to angle-closure glaucoma and hypertension

Question 15

What might atropine interact with?

Answer 15

• SSRIs
• TCAs
• Haloperidol
• Other anti-muscarinic agents
• Codeine
• Levodopa

Question 16

What might happen if atropine is given with SSRIs?

Answer 16

Increased antimuscarinic side effects of atropine

Question 17

What might happen if atropine is given with TCAs?

Answer 17

Increased antimuscarinic side effects of atropine

Question 18

What might happen if atropine is given with haloperidol?

Answer 18

Increased antimuscarinic side effects of atropine

Question 19

What might happen if atropine is given with other anti-muscarinic agents?

Answer 19

Increased antimuscarinic side effects of atropine

Question 20

What might happen if atropine is given with codeine?

Answer 20

Increased antimuscarinic side effects of atropine

Question 21

What might happen if atropine is given with levodopa?

Answer 21

Reduced absorption of atropine

Question 22

What monitoring is required with atropine?

Answer 22

Close monitoring of vital signs and ECG in emergency use of atropine during bradycardia

Question 23

Why is close monitoring required when atropine is being used for bradycardia?

Answer 23

The effects of atropine wear off quickly due to its short half life

Question 24

What are the common side effects of atropine?

Answer 24

• Increased HR
• Reduction in secretions, e.g. dry mouth
• Urinary retention
• Dilated pupils resulting in blurred vision
• Constipation

Question 25

Why is patient counselling sometimes not possible in atropine?

Answer 25

As the drug is given in emergency situations, e.g. life threatening bradycardia

Question 26

What counselling should be given to patients started on atropine in a non-emergency setting?

Answer 26

Inform patient atropine tablets should be swallowed whole, and warn patients about the anti-muscarinic side-effects