About beta blockers
Beta blockers are prescribed for a variety of cardiovascular conditions, yet studies have shown that they might be underutilized. Conditions treated with beta blockers include:
- High pressure blood (hypertension). The exact mechanism of how beta blockers lower blood pressure is unknown. There are a variety of effective antihypertensive medications available and physicians consider a number of factors when recommending a medication. In general, beta blockers are not considered first-line therapy for high blood pressure, but may be added to an antihypertensive regimen, either as a stand-alone drug or in combination with other blood pressure lowering drugs. Some studies have also examined beta blockers among different age or racial groups. In general, younger patients were shown to respond better to beta blockers than older patients.
- Angina (chest pain), pressure or discomfort caused by a lack of oxygen-rich blood to the heart. Beta blockers are considered a first-line treatment for chronic stable angina, especially if the angina is consistently induced by exercise. They reduce the heart’s demand for oxygen by slowing the heartbeat and decreasing the force of the contraction. Among these patients, research has found that beta blocker use can decrease the risk of repeat heart attacks and death, in addition to improving exercise capacity and decreasing the frequency of angina episodes. Beta blockers can even allow patients to postpone surgeries until they no longer respond to medication or their condition become unstable.
- Heart attack. Beta blockers are important tools to help treat acute heart attacks and prevent repeat heart attacks. Among heart attack patients, beta blockers have been shown to decrease the oxygen demands of the heart muscle, decrease the risk of dangerous heart rhythms and improve the heart function. Once treatment with a beta blocker has begun in a heart attack patient, therapy is usually indefinite. Beta blockers should not be administered to heart attack patients who also suffer from asthma, severe bradycardia (abnormally slow heart rhythm) and fluid retention of the lungs.
- Heart failure, a condition in which at least one chamber of the heart is not pumping well enough to meet the body’s demands. At one time, beta blockers were avoided in the treatment of heart failure patients whose left ventricles did not function optimally. However, numerous studies have since shown that beta blockers are an effective treatment for heart failure and may significantly improve the survival rates of heart failure patients. As a result, they are prescribed to virtually all heart failure patients. New studies have also found that heart failure patients that are treated with beta blockers before, during and after hospitalization have better outcomes. Also, combination therapy of beta blockers and statins has been effective in preventing a second heart attack in patients who developed heart failure following a heart attack.
- Abnormal heart rhythms (arrhythmias) or extra beats (palpitations). Research has also shown benefit with beta blockers in preventing postoperative atrial fibrillation.
- Prior to coronary artery bypass surgery (CABG). Beta blocker use prior to bypass surgery has been found to increase survival rates, as well as reduce the risk of complications in high-risk patients (e.g., need for mechanical ventilation or follow-up surgery, kidney failure, heart attack, stroke).
- Prior to and following a multitude of non-cardiac (heart) surgeries, particularly those involving a vascular procedure. Beta blockers, when used before and continued for at least one month after surgery, help prevent a heart attack following the operation. This includes peripheral vascular surgeries, but also any of the higher risk, general, non-cardiac surgeries. Beta blocker use before and after surgery has proved beneficial to those with known coronary artery disease (CAD), and those in whom CAD is only suspected by the presence of vascular disease in other parts of the body (e.g., peripheral vascular disease).
- Hypertrophic cardiomyopathy. A condition characterized by an abnormal growth of muscle fibers on the heart muscle, often causing a thickened septum (the muscle wall separating the heart’s chambers).
- Hyperthyroidism (overactive thyroid gland). Beta blockers have been found to relieve some symptoms associated with this condition.
- Migraine headaches or headaches with sexual activity (HSA). Beta blockers may prevent migraines and/or HSAs in some patients.
- Anxiety or tremors. They are sometimes beneficial in treating panic attacks.
- Glaucoma. In addition to beta blockers used directly on the eye area (e.g., levobunolol, metipranolol), systemic beta blockers are also available (e.g., timolol).
Conditions of concern
Patients should discuss with their physician the benefits and risks of taking beta blockers if they have been diagnosed with any of the following conditions:
- Bradycardia (abnormally slow heart rates). Beta blockers can further reduce the heart rates of these patients to dangerously low levels, increasing the risk of heart failure, angina and loss of consciousness.
- Heart block (partial or complete loss of electrical communication between the chambers of the heart).
- Asthma, emphysema or bronchitis. Beta blockers can cause constriction of tiny air tubes (bronchioles), possibly worsening these lung diseases.
- Chronic obstructive pulmonary disease (COPD). Beta blockers may aggravate this condition and should be avoided in patients with severe COPD. Among patients with mild to moderate disease, they should be used at low doses or possibly in combination with another medication.
- Peripheral vascular disease. Beta blockers may cause worsening of symptoms among patients with vascular disease, including cold extremities and, in some cases, tissue death and gangrene.
- Kidney or liver disease. These conditions may cause beta blockers to be removed from the body at a slower rate, increasing the risk of overdose and/or side effects.
- Diabetes. Beta blockers may mask the symptoms of hypoglycemia (low blood sugar) and slow or impair the body’s recovery from an episode of insulin-induced hypoglycemia.
- Insulin resistance and metabolic syndrome, two known risk factors for heart attack. Beta blockers may increase blood sugar (glucose) levels.
In addition, beta blockers may make the following disorders worse:
- Raynaud syndrome. A painful condition caused by the temporary constriction of the small arteries in the hands and feet.
- Psoriasis. A chronic skin condition characterized by red patches with white scales.
- Clinical depression or a history of this condition.
- Myasthenia gravis. A progressive weakness of voluntary muscles.
- Side effects
Potential side effects of beta blockers
Depending on the type of beta blocker prescribed, patients may experience one or more side effects, including:
- Allergic reaction (sneezing, respiratory congestion, itching or skin rashes)
- Bradycardia (slow heart rate)
- Worsening of heart failure
- Drowsiness, weakness or fatigue
- Cold hands and feet, or an increased general sensitivity to cold
- Dizziness or lightheadedness, especially after getting up from a standing or lying position
- Headache or ringing in ears (tinnitus)
- Shortness of breath (dyspnea) or wheezing
- Fainting (syncope)
- Vivid dreams, nightmares, depression, memory loss and (rarely) hallucinations
- Increase in cholesterol levels
- Increased insulin resistance (except with carvedilol)
- Erectile dysfunction (impotence)
- Reduced sex drive in both men and women
- Abdominal cramps or (rarely) diarrhea, constipation and/or nausea
Patients who experience side effects from beta blockers should contact their physician immediately, but should not stop taking the medication. Abrupt discontinuation may lead to angina or heart attack in patients with coronary artery disease. Stopping beta blocker use too quickly can also worsen the symptoms of patients who have an underactive thyroid (hypothyroidism). Therefore, all patients are encouraged to speak to their physicians before making any changes in how they are taking beta blockers.
Drug or other interactions
Patients should consult their physicians before taking any other medication (either prescription or over-the-counter), nutritional supplements or herbal remedies. Of particular concern for individuals taking beta blockers are:
- Antiarrhythmics or antihypertensives (drugs that slow heart rate or lower blood pressure) such as calcium channel blockers or ACE inhibitors. Combined, these medications may lower blood pressure to unsafe levels. However, lower doses of these medications are routinely prescribed along with beta blockers in patients who do not respond to other therapies. Some medications even combine more than one antihypertensive into a single pill.
- Antacids containing aluminum. These may reduce the absorption and, therefore, the effectiveness of beta blockers. Patients should consult their physicians before using these substances.
- Alcohol. May reduce the absorption and, therefore, the effectiveness of beta blockers. Patients should consult their physicians about how much alcohol is safe to drink while on beta blockers.
- Caffeine. May reduce the effects of beta blockers. Patients should consult their physicians about how much caffeine is safe to drink while on beta blockers.
- Insulin and other antidiabetic drugs. Taking beta blockers may result in the need to adjust the dosages of these antidiabetic drugs because of their effect on glucose metabolism (low blood sugar) in diabetic patients.
- Monoamine oxidase inhibitors (MAO-Is). Taking beta blockers within two weeks of an MAO-I can result in severe high blood pressure (hypertension). Patients should inform physicians of all medications they are currently taking, or have recently been taking, before filling their beta blocker prescription.
- Allergy shots or skin tests. Combination with beta blockers may produce severe allergic reactions.
- Nonsteroidal anti-inflammatory drugs (NSAIDs). These drugs (e.g., aspirin and ibuprofen) can decrease the effectiveness of the beta blockers.
- Bronchodilators. Medications to treat asthma, bronchitis, emphysema or other lung diseases.
In some cases, physicians will prescribe other medications in combination with beta blockers, such as diuretics (medications that reduce the amount of fluid retained in the body by increasing urine flow). Because diuretics and beta blockers are often prescribed together to treat high blood pressure, they are sometimes available in a single combination pill. The generic names of these combination pills will contain the names of both medications. For example “bisoprolol hydrochlorothiazide” is a single tablet containing both bisoprolol (a beta blocker) and hydrochlorothiazide (a thiazide diuretic).
Patients should never stop taking beta blockers abruptly. Doing so may lead to angina or heart attack in patients with coronary artery disease or the worsening of symptoms for patients with other conditions (e.g., hyperthyroidism). Patients who need to stop this medication should do so gradually while under a physician’s guidance.
Most patients on beta blockers to treat high blood pressure (hypertension) will be taking the medication for the rest of their lives, provided no serious side effects occur. Patients should remember that beta blockers control high blood pressure, but do not cure it. Even if blood pressure is successfully lowered, patients should continue taking their medication exactly as directed and keeping all scheduled follow-up appointments with their physicians. Also, patients should take and record their blood pressure readings regularly, reporting anything unusual to their physicians.
Patients on beta blockers should measure their heart rate for a full minute periodically. If it is 50 beats per minute or lower, patients should contact their physician. Patients being treated for heart failure may need to weigh themselves frequently and report a gain of more than 5 pounds in one week to their physicians.
Beta blockers affect circulation, and some people may become more sensitive to cold. Patients should take additional precautions when engaging in outdoor winter activities. In addition, they should inform all of their medical and dental care providers that they are taking beta blockers.
Patients who are allergic to foods, medicines or insect stings should be aware that this medication may worsen their reactions to these allergies.
- How to use
Pregnancy use issues
Use of beta blockers during pregnancy may cause low blood sugar, breathing problems, a slow heart rate and low blood pressure in the newborn. However, if the mother’s condition warrants the use of beta blockers during pregnancy, they can be used under her physician’s guidance. Patients should inform their physicians if they are pregnant or trying to become pregnant before beginning any medication.
When breast feeding, some beta blockers will pass from mother to infant and others may reduce the flow of breast milk. This may cause a slow heartbeat, low blood pressure or breathing difficulties in the nursing infant. Therefore, an alternative feeding method may be recommended when beta blockers are being used. Parents should weigh the benefits and risks with their physicians.
Child use issues
Currently, there is no evidence that the risk of children’s side effects from beta blockers is different from those of adults. However, the safety of beta blocker use in children has not yet been scientifically established. Parents are encouraged to discuss the potential risks and benefits with a pediatric cardiologist before their children begin beta blocker treatments.
Elderly use issues
Beta blockers are frequently prescribed for elderly patients. Generally, older patients require lower doses of beta blockers. Older adults also have a higher frequency and intensity of side effects, such as dizziness. In addition, beta blockers may reduce the older patient’s ability to tolerate cool temperatures.
Questions for your doctorPatients may wish to ask their doctor the following questions related to beta blockers:
- Why are you recommending beta blockers for my condition?
- Which beta blocker are you recommending for me and why?
- How long before this medication takes effect? How will we know that it is working?
- If this medication doesn't work, what are my options?
- Am I taking any medications that may affect beta blockers?
- Do I have any medical conditions that might conflict with the use of beta blockers?
- What are the likely side effects with this medication?
- What side effects or changes will indicate a medical emergency?
- How will I be monitored with the medication?
- Will I need any tests on a regular basis?
- Are there any foods or beverages that will affect the function of this medication?
- Do I need to stop using any specific drugs while I am on beta blockers?
- Will I be on beta blockers for the rest of my life?
- Can I use beta blockers if I am pregnant or nursing?
- How will beta blockers affect my diabetes?