CV Antimuscarinics, CV and GI uses,Atropine, hyoscine butylbromide,glycopyrronium

Question 1

What is atropine used for?

Answer 1

First line management of bradycardia

Question 2

What is hyoscine butylbromide used for?

Answer 2

First-line pharmacological treatment option for irritable bowel syndrome (IBS), where they are used for their antispasmodic effect.

Question 3

What about in end of care life?

Answer 3

In the care of the dying patient, antimuscarincs (e.g. hyoscine butylbromide) may have a role in reducing copious respiratory secretions.

Question 4

Mechanisms of action?

Answer 4

Antimucarinic drugs bind to the muscarinic receptor, where they act as a competive inhibitor of acetylcholine

Question 5

In blocking the receptor, what effects do anti muscarinics have?

Answer 5

They increase heart rate and conduction; reduce smooth muscle tone and peristaltic contraction, including in the gut and urinary tract; and reduce secretions from glands in the respiratory tract and gut. In the eye they cause relaxation of the pupillary constrictor and ciliary muscles, causing pupillary dilatation and preventing accommodation, respectively.

Question 6

Important adverse effects?

Answer 6

1. Tachycardia
2. Dry mouth
3. Constipation
4. Urinary retention
5. Blurred vision
6. Atropine has central effects: drowsiness, confusion

Question 7

Practical prescribing?

Answer 7

1. Atropine for bradycardia:IV 300-600mcg every 1-2mins
2. IBS: As hyoscine butylbromide(buscopan) 10mg 8hrly
3. For control of respiratory secretions hyoscine butylbromide or hyoscine hydrobromide is usually given SC, either by injection or as part of a continuous subcutaneous infusion.