Cardiology - Beta-Blockers

Why are beta-blockers useful?

Beta-blockers are a class of drugs used to control symptoms of heart failure that are made worse by certain hormones called catecholamines.

The body releases these hormones as part of its response to heart failure. For this and other reasons, beta-blockers have been shown to be effective for treating most people who have heart failure.

Beta-blockers have a variety of effects throughout the body. They are used to treat:

• Heart disease that causes chest pain
• High blood pressure
• Heart attacks, and irregular or rapid heartbeats

Beta-blockers are also used to prevent migraine headaches, treat tremors, and control anxiety.

• Beta-blockers may work by slowing the heart rate, which allows the left ventricle (the main pumping chamber of the heart) to fill more completely
• Some of these medicines may also help open or widen blood vessels in the body. This makes them especially useful in some people with certain forms of heart failure who may also have high blood pressure
• Bisoprolol, Carvedilol, and Nebivolol are some of the Beta- blockers that have been tested for use in the treatment of heart failure

How are they given?

Beta-blockers should be used together with other medicines that are usually used to treat heart failure, such as angiotensin converting enzyme inhibitors (ACEi) or diuretics.

The effect of Beta-blockers may depend on the dosage used. A lower dose may have a different effect than a higher dose.

Beta-blocker therapy should be started at a low dose and increased slowly over time. The heart failure specialist nurse will carefully adjust the dose of the Beta-blocker to suit the individual.

It may take 2 to 3 months to see the effects of Beta-blocker medicine.

Are there any side effects?

Beta-blockers may sometimes cause a drop in blood pressure when a person stands up resulting in dizziness and rarely, fainting. Other less common side effects are:

• Slow heartbeat (bradycardia)
• Fatigue
• Depression
• Increased wheezing in people with asthma
• Erection problems
• Cold hands and feet

A few days after starting or increasing Beta-blockers a small number of patients may notice a worsening of heart failure. It can cause symptoms such as:

• Increasing shortness of breath
• Weight gain
• And/ or swollen ankles

If this should happen contact your heart failure specialist nurse or general practitioner and arrangements will be made to review you.

Points to remember

• Beta-blockers may not begin to relieve symptoms immediately. Long term administration is required to induce benefit
• You may feel worse at first before you feel better
• If you do experience a worsening of your heart failure this does not prevent you from reaching the target dose – it may just take a little longer to get there
• The most common side effects are dizziness, tiredness and headaches
• Side effects are usually mild and gradually resolve before the dose is adjusted again
• If you do experience side effects, please report them
• Continue to take your Beta-blocker unless instructed otherwise
• Discuss any fears or worries that you have