Beta-Blockers Flashcards
Give 5 examples of cardioselective beta blockers?
- Atenolol
- Bisoprolol
- Celiprolol
- Metoprolol
- Acebutolol
Give 5 examples of non-cardioselective beta-blockers?
- Nadolol
- Oxprenolol
- Propanolol
- Sotalol
- Timolol
What is meant by a cardioselective beta-blocker?
They primarily target beta-adrenoceptors in the heart
What is the advantage of cardioselective beta blockers?
They cause fewer effects on end organs outside the heart
What do non-cardioselective beta blockers target?
Beta-adrenoceptors in the heart and other end organs
What is the mechanism of action of beta blockers?
They inhibit stimulation of beta-adrenoceptors in the heart (if selective) and in vascular smooth muscle, bronchi, and other organs, e.g. liver and pancreas (if not selective)
What does the beta blockade in the heart result in?
Reduction in heart rate and force of contraction
What does beta blockade outside of the heart result in?
Vasoconstriction and bronchoconstriction
What are the routes of delivery of beta blockers?
- PO
- IV
- Topical
Give an example of when beta-blockers may be used IV?
IV metoprolol in atrial fibrillation
Give an example of when beta blockers may be used topically?
In treatment of glaucoma
What are the indications for beta-blockers?
- Hypertension
- Chronic heart failure
- Ischaemic heart disease, especially post-MI prophylaxis and treatment of angina
- AF, atrial flutter, and SVT
- Anxiety
- Migraine
- Thyrotoxicosis
- Primary open angle glaucoma
What beta blocker is used for hypertension in pregnancy?
Labetalol
Why should beta blockers not be used in acute heart failure?
Risk of deterioration
What beta blocker is used in anxiety?
Propanolol
What are the contraindications to beta-blockers?
- Asthma
- 2nd or 3rd degree heart block
- Sick sinus syndrome
- Uncontrolled heart failure
- Bradycardia and hypotension
- Metabolic acidosis
- Severe peripheral arterial disease
Who should beta-blockers be used with caution in?
- History of obstructive airway disease
- Diabetic patients
- Hyperkalaemia
What should be done if beta-blockers are used in patients with history of obstructive airway disease?
Use cardioselective type under close supervision
What should diabetic patients on beta-blockers be warned about?
Beta blockers may mask signs of hypoglycaemic attack
What might beta blockers interact with?
- Other anti-hypertensive drugs
- Verapamil
What might happen if beta-blockers are given with other anti-hypertensive drugs?
May cause hypotension
What might happen if beta-blockers are given with verapamil?
Complete heart block or significant blood pressure drop can occur
What monitoring is required with beta blockers?
Monitor lung function of patients with obstructive airway disease who are taking beta blockers
What are the common side effects of beta blockers?
- Fatigue
- Headache
- Dizziness
- Erectile dysfunction
- Sleep disturbance and nightmares
- Cold peripheries
What are the less common side effects of beta blockers?
May worsen Raynaud’s disease
Why do beta-blockers have slightly different adverse effect profiles?
Because they vary in their lipid or water solubility, which results in a slightly different adverse effect profile
Give 3 examples of beta blockers that are more soluble in water
- Atenolol
- Nadolol
- Sotalol
What is the result of beta blockers being more soluble in water?
Less likely to cross blood-brain barrier and cause less disturbance to sleep
What patient counselling is required with beta blockers?
- Side-effects
- Risk of breathing problems in asthmatics and patients with COPD
- Risk of hypoglycaemia in diabetics
- Compliance
- Withdrawal
- Overdose
What advice should be given to patients with asthma/COPD on beta-blockers?
They should call an ambulance if having breathing difficulties
kinda irrelevant cut shouldn’t be on them anyway
What needs to be discussed regarding compliance with beta blockers?
Emphasise should not stop taking their beta blocker unless advised by their doctor
Why is it important that the patient does not stop taking their beta blocker unless advised by doctor?
Likely that their body is used to the drug, and when they stop taking it may suffer from ‘rebound’ symptoms such as worsening chest pain or arrhythmias
How is withdrawal avoided with beta blockers?
If needs to be stopped, normally dose reduction is undertaken over 7-14 days and is important that withdrawal is supervised
What should be discussed regarding overdose with beta-blockers?
The adverse effects of a beta blocker overdose are unpredictable, and can be dangerous, hence medical help should be sought immediately
