From the Guidelines
Beta blockers are a class of medications that play a crucial role in reducing morbidity and mortality in patients with heart failure, and their use is recommended for all patients with current or prior symptoms of HFrEF, unless contraindicated, as stated in the 2013 ACCF/AHA guideline 1.
Definition and Mechanism
Beta blockers are medications that block the effects of adrenaline (epinephrine) on beta-adrenergic receptors in the body, primarily affecting the heart and blood vessels. They work by slowing the heart rate, reducing the force of heart contractions, and decreasing blood pressure. Common beta blockers include metoprolol, atenolol, propranolol, carvedilol, and bisoprolol.
Clinical Uses
These medications are primarily used to treat:
- High blood pressure
- Heart failure
- Abnormal heart rhythms
- Angina (chest pain)
- Prevention of future heart attacks in people who have already had one They're also prescribed for non-cardiac conditions like:
- Migraine prevention
- Essential tremor
- Anxiety
- Glaucoma
Dosing and Side Effects
Typical dosing varies by medication and condition. For example, metoprolol might be started at 25-50mg twice daily for hypertension, while propranolol for anxiety might begin at 10-20mg as needed. Side effects can include:
- Fatigue
- Cold hands/feet
- Dizziness
- Sleep disturbances Beta blockers should not be stopped suddenly as this can trigger serious cardiac events; dosage must be gradually reduced under medical supervision.
Benefits in Heart Failure
Long-term treatment with beta blockers can lessen the symptoms of HF, improve the patient’s clinical status, and enhance the patient’s overall sense of well-being, as noted in the 2013 ACCF/AHA guideline 1. They can reduce the risk of death and the combined risk of death or hospitalization, with benefits seen in patients with or without CAD and in patients with or without diabetes mellitus, as well as in women and blacks.
Selection of Beta Blockers
Beta-1 selective agents are preferred due to advantages concerning side-effects and precautions when compared with non-selective beta-blockers, as stated in the guidelines on the management of stable angina pectoris 1. Commonly used beta-1 blockers with good documentation as anti-anginal drugs are metoprolol, atenolol, and bisoprolol. Target doses for full anti-anginal effects are: bisoprolol 10 mg o.d., metoprolol CR 200 mg o.d., atenolol 100 mg/day o.d. (or 50 mg b.i.d.).
From the FDA Drug Label
Beta-adrenergic blocking agents Beta-blockers should be avoided in overt congestive heart failure, Beta-adrenergic blockade may prevent the appearance of certain premonitory signs and symptoms Beta-blockade may precipitate more severe failure Chronically administered beta-blocking therapy
Beta blockers are a class of medications that block the effects of the hormone epinephrine, also known as adrenaline, and norepinephrine on the body's beta receptors, which are found in the heart, lungs, and other areas. They are used to treat various conditions, including high blood pressure, angina, and certain heart-related issues. In the context of propranolol, beta blockers can have significant effects on the heart and circulatory system, and their use requires careful consideration of potential risks and benefits 2.
From the Research
Definition of Beta Blockers
- Beta blockers are a class of drugs that act by antagonizing the actions of the endogenous adrenergic agonists epinephrine and norepinephrine at the beta-adrenergic receptors 3
- They are used to treat various cardiovascular disorders, including hypertension, angina pectoris, and heart failure 4, 5, 6
Mechanism of Action
- Beta blockers work by blocking the effects of epinephrine and norepinephrine on the heart and blood vessels, which helps to reduce heart rate, blood pressure, and myocardial oxygen demand 3
- They can be selective or non-selective, with selective beta blockers targeting specific beta-adrenergic receptors (e.g. beta-1 or beta-2) 3
Types of Beta Blockers
- Examples of beta blockers include metoprolol, atenolol, propranolol, bisoprolol, and carvedilol 4, 3, 5, 6
- Some beta blockers, such as pindolol, have intrinsic sympathomimetic activity, which means they can cause some sympathetic stimulation under certain conditions 3