Primarily used to treat cardiovascular diseases
Beta receptors
Beta receptors exist in three distinct forms:
- beta-1 (B1)
- beta-2 (B2)
- beta-3 (B3).
Beta-1 receptors – primarily in the heart
Beta-2 receptors- diverse location in many organ systems, control various aspects of metabolic activity and induce smooth muscle relaxation.
Beta-3 receptors induce the breakdown of fat cells and are less clinically relevant at present.
Indications
- tachycardia,
- hypertension,
- myocardial infarction,
- congestive heart failure,
- cardiac arrhythmias,
- coronary artery disease,
- hyperthyroidism,
- essential tremor,
- aortic dissection,
- portal hypertension,
- glaucoma,
- migraine prophylaxis
Less common conditions such as –
- long QT syndrome
- hypertrophic obstructive cardiomyopathy
Heart failure
Specifically, the beta-blockers bisoprolol, carvedilol, and metoprolol succinate are the agents chosen.
Metoprolol tartrate is not indicated for heart failure and is instead used for other conditions such as atrial fibrillation.
Contraindications
- beta-blockers have been contraindicated in asthmatic patients.
- cardio-selective beta-blockers, also known as beta-1 selective can be given
- Non-selective beta-blockers should not be used in patients with asthma.
- Acute or chronic bradycardia and/or hypotension have relatively contraindication to beta-blocker usage.
- Patients diagnosed with long QT syndrome or who have had torsades de pointes in the past should not use the drug sotalol.
- Raynaud phenomenon- should avoid beta-blockers due to the risk of exacerbation.
