Beta blockers have two key effects on the cardiac muscle; reducing the rate and force of myocardial contraction along with reducing the arterial blood pressure. Both effects reduce cardiac workload and myocardial oxygen demand.

The following beta-blockers are licensed for the treatment of angina: propranolol, acebutolol, atenolol, bisoprolol, carvedilol, metoprolol, nadolol, nadolol, oxprenolol, pindolol and timolol. 

There is no good evidence that any one beta-blocker is better than any other in the management of stable angina.

The efficacy of beta-blockers is thought to be due to a class effect rather than the effects of individual drugs.

• • Factors such as comorbidity, compliance, and cost should be considered when selecting a beta-blocker.
  • Occasionally, an individual may respond better to one beta-blocker than another.
  • Atenolol, bisoprolol, and metoprolol are cardioselective and do not exhibit intrinsic sympathomimetic activity.
  • For people who have had a previous myocardial infarction, metoprolol (standard release), propranolol (standard release), timolol, or atenolol may be preferred.

Beta blocker choice may be influenced by other co-morbidities. Patients who have previously had an MI may be prescribed metoprolol, propranolol, timolol or atenolol whilst in patients suffering heart failure bisoprolol, carvedilol or nebivolol may be more appropriate.¹

Acute attacks of angina are commonly associated with episodes of tachycardia; the rate controlling action of beta blockers is beneficial in countering this effect.

Reducing the heart rate increases the diastolic period which improves coronary perfusion by increasing the time for coronary blood flow.

Patients prescribed beta blockers should be counselled not to abruptly stop taking their treatment as this has been shown to increase the risk of cardiovascular events.

Common side effects associated with beta blockers include bradycardia, hypotension, cold extremities, fatigue, lethargy and impotence. Beta blockers can cause nightmares or sleep disturbances although this is less likely with water soluble beta blockers because of reduced passage across the blood brain barrier.

Non selective beta blockers can also mask the signs of hypoglycaemia so cardioselective agents should be used in patients with diabetes.

Patients should be advised to discuss their treatment with the GP if these side effects become problematic.