What Are Beta-Blockers?
Beta-blockers, beta-adrenergic blocking agents, are an effective class of medications used to treatsystolic heart failure by disrupting the effects of the hormone epinephrine (adrenaline).1-6 Like ACE inhibitors, they widen blood vessels to lower blood pressure, improve blood flow, and decrease the workload on the heart.1-2 They cause the heart to beat slower and with less force.1
Beta-blockers come in two forms. Non-cardioselective that block both beta-1 and beta-2 receptors and cardioselective that block beta-1 receptors.3 There are both beta-1 and beta-2 receptors in the heart. Beta-2 receptors are also in blood vessels and the muscle lining the airways.1,3
Cardioselective beta-blockers block hormonal stimulation of the heart which helps reduce systolic pressure, heart rate, the force of muscle contraction, as well as improving oxygenation and increasing exercise tolerance.3 Non-cardioselective agents decrease the activity of the heart. They block receptors in the heart that help to reduce systolic pressure, heart rate, and the force of contractions and output. They also minimize arrhythmias and increase exercise tolerance.
Why are they prescribed?
Beta-blockers have multiple indications. Beta-blockers are prescribed for people with systolic HF who have symptoms and for those who are asymptomatic (without symptoms).1 They also treat heart disease that causes chest pain, high blood pressure, heart attacks, cardiomyopathy, and arrhythmias. Beta-blockers also have non-cardiac indications; they are used to prevent migraine headaches, treat tremors, and control anxiety.4
Beta-blockers reduce the workload of the left ventricle thereby improving symptoms, helping people to feel better and live longer lives. They are used to treat both systolic and diastolic heart failure. By slowing the heart rate there is more time for the left ventricle to fill with blood which increases the volume that the heart can pump with each contraction.4
Non-cardioselective beta-blockers are not typically prescribed for people with asthma or other respiratory conditions because the medication may trigger bronchial constriction which could cause severe asthma attacks. Caution should also be taken by diabetics because these beta-blockers may mask indications of low blood sugar like a rapid heartbeat.1,3
Beta-blockers are typically prescribed to prevent, treat or improve symptoms for people with:1
- Irregular heart rhythm (arrhythmia)
- Heart failure
- Chest pain (angina)
- Heart attacks
- Certain types of tremors
For patients with systolic heart failure, there are only 3 beta-blockers that have been shown to limit or reverse the damage done to the heart, improve symptoms, decrease the risk of hospitalization for heart failure, and prevent death.2 They are carvedilol, bisoprolol, and metoprolol succinate.
Commonly prescribed Beta-blockers inhibitors include:5-6
- Zebeta®, Ziac®- (bisoprolol)
- Coreg® - (carvedilol)
- Toprol XL®- (metoprolol succinate)
- Sectral®- (acebutolol)
- Tenormin®- (atenolol)
- Kerlone® - (betaxolol)
- Normodyne®, Trandate®- (labetalol)
- Lopressor® - (metoprolol)
- Corgard® - (nadolol)
- Bystolic®- (nebivolol)
- Levatol®- (penbutolol)
- Visken®- (pindolol)
- Inderal® - (propranolol)
- Betapace® - (sotalol)
- Blocadren® - (timolol)
There are different dosages for each of these formulations, and people with HF may be prescribed different dosages at different points to manage their symptoms.
Common side effects of beta-blockers include cold hands or feet, fatigue, dizziness, or weight gain.1-2 Medications can take time to work properly and to get used to. It may take a few weeks before both symptoms and side effects go away and you begin to feel better. This is true when starting or changing doses of beta-blockers.2,4 When using beta-blockers some people experience increased symptoms including fatigue and shortness of breath. Communicate with your provider if you have unusual weight gain, fluid buildup or continued dizziness as these may be signs that you need a dose adjustment to the medication.2
As with most heart failure medications, your provider will generally order regular blood tests to evaluate its effectiveness and any side effects.1 It is also important to regularly check your pulse to make sure it is not too slow.4 You may be more sensitive to exposure to sun and cold, and grapefruit juice may interfere with the effectiveness of beta-blockers.
It is important to take all medicines as prescribed. This will improve the effectiveness of the medication and may reduce any complications. Be sure to tell your provider about all medications to avoid any drug interactions. If you have difficulty taking your medications, do not stop on your own, contact your health care team for assistance.
These are not all the possible side effects of beta-blockers. Patients should talk to their doctor about what to expect with treatment with beta-blockers.
If you have trouble breathing, or sudden chest pain call 911 or other emergency services or go directly to an emergency room.