Beta-Blockers

Question 1

What are examples of beta-blockers?

Answer 1

• Bisoprolol
• Atenaolol
• Propranalol
• Metoprolol

Question 2

What are beta-blockers indicated for?

Answer 2

• Ischaemic heart disease
• Chronic heart failure
• Atrial fibrillation
• Supraventricular tachycardia (SVT)
• Hypertension

Question 3

How are beta-blockers used in ischaemic heart disease?

Answer 3

Improve symptoms and prognosis with acute angina and ACS

Question 4

How are beta blockers used in chronic heart failure?

Answer 4

First-line to improve prognosis

Question 5

How are beta blockers used in AF?

Answer 5

First-line option to reduce ventricular rate, and, in paroxysmal AF, maintain sinus rhythm

Question 6

How are beta blockers used in hypertension?

Answer 6

Used when other medications (CCB, ACEi or thiazide) ineffective

Question 7

How do beta blockers work?

Answer 7

Via the β1-receptor, β-blockers reduce force of contraction and speed of conduction in the heart. This relieves myocardial ischaemia by reducing cardiac work and oxygen demand, and increasing myocardial perfusion

Question 8

How do beta blockers improve prognosis in heart failure?

Answer 8

‘protecting’ the heart from the effects of chronic sympathetic stimulation

Question 9

How do beta blockers slow ventricular rate in AF?

Answer 9

Prolong the refractory period of the AV node

Question 10

How do beta blockers work in SVT?

Answer 10

B-blockers may break any re-entry circuits and restore sinus rhythm

Question 11

How do beta-clockers work in hypertension?

Answer 11

Lower blood pressure through a variety of means, one of which is by reducing renin secretion from the kidney, since this is mediated by β1-receptors

Question 12

What are important adverse side effects of beta-blockers?

Answer 12

• Fatigue
• Cold extremities
• Headache
• GI upset
• Sleep disturbance/nightmares

Question 13

When are beta-blockers contraindicated?

Answer 13

• Asthma
• Acute heart failure
• Haemodynamic instability
• Heart block

Question 14

Why are beta-blockers contraindicated in asthmatics?

Answer 14

Cause bronchospasm through blockade of B2 adrenoreceptors

Question 15

What are important interactions to consider when prescribing beta blockers?

Answer 15

Non-dihydropyridine CCB (verapamil, diltiazem)

Question 16

What dose of Bisoprolol would you start someone on for hypertension?

Answer 16

5mg daily - can go up to 10 mg daily

Question 17

What is the starting dose of bisoprolol in heart failure?

Answer 17

1.25 mg once daily (in the morning)

Question 18

What dose of atenolol tablets would you give for hypertension?

Answer 18

50 mg once daily

Question 19

What dose of atenolol tablets would you give someone with angina?

Answer 19

25-100 mg daily - either once or twice per day

Question 20

What dose of atenolol tablets would you consider giving someone for arrythmias?

Answer 20

50-100 mg daily

Question 21

What dose of atenolol tablets would you consider giving someone post MI?

Answer 21

25 mg daily initially, increasing to 10 mg daily

Question 22

What is metoprolol used for?

Answer 22

Assuring bradycardia during CT coronary angiogram

Question 23

What is propranalol mainly used for?

Answer 23

• Anxiety relief
• Essential tremor
• Thyrotoxicosis
• Migraine prophylaxis

Question 24

How would you monitor B-blocker efficacy?

Answer 24

Symptoms (chest pain) and heart rate

Question 25

What general approach is taken with using beta blockers acutely?

Answer 25

Best to select drug with relatively short half-life (e.g standard release metoprolol) - more responsive to dose adjustment and can be stopped wuickly if necessary