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Beta BlockersBeta-Adrenergic Blockers, Beta 1 Blockers, Beta 2 Blockers, B-BlockersBeta blockers are medications that reduce the workload of the heart and lower blood pressure. They are commonly prescribed to relieve angina (a certain type of chest pain, pressure or discomfort) or to treat congestive heart failure. They are also prescribed for people who have high blood pressure (hypertension). Patients who take beta blockers may experience side effects such as a very slow heart rate (bradycardia), dizziness or increased tiredness. Patients may also become more sensitive to cold. However, patients are urged to not stop taking beta blockers abruptly, unless ordered to do so by their physician. Otherwise, they could experience a rebound effect that increases their risk of angina and heart attack. Any unusual symptoms resulting from taking beta blockers should be reported to one’s physician. What are beta blockers?First used in the 1960s, beta blockers are medications that reduce the workload of the heart by blocking certain actions of the sympathetic nervous system (e.g., the stress response) that could lead to a rapid heartbeat. They are called “beta blockers” because they block the microscopic areas in the heart called beta receptors. Like alpha receptors, these beta receptors are normally activated by certain hormones released during stress (e.g., adrenaline). When activated by these hormones, the beta receptors trigger a reaction that speeds the heart rate and increases the force of the heartbeat. However, this reaction can be inhibited if the chemicals are blocked by beta blockers from activating or “binding to” the beta receptors. Therefore, beta blockers relieve cardiac stress by slowing the heart rate and reducing the force of heart muscles contractions (the pumping action). They also reduce blood vessel constriction in the heart, brain and body. There are two types of beta blockers, which are classified according to the type of beta receptor that they block (beta 1 or beta 2):
The dosage of the beta blocker will affect how it acts in the body. Physicians usually begin by prescribing a very low dosage, and then increasing it as needed. Rapidly introducing beta blockers can lead to an abnormally slow heartbeat, causing lightheadedness, loss of consciousness or acute congestive heart failure. Beta blockers can be prescribed as tablets, time-release capsules or concentrated oral solutions. The medication generally begins to affect body systems within one to four hours after each dose. What are some types of beta blockers?Today’s beta blockers include medications such as the following:
For what conditions may beta blockers be prescribed?Beta blockers are prescribed for a variety of cardiovascular conditions, including the following:
In addition, beta blockers are sometimes prescribed for migraine headaches, glaucoma, hereditary tremors or hyperthyroidism. What conditions indicate cautious use of beta blockers?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:
Beta blockers may make the following disorders worse:
The effect of certain beta blockers may be undesirably strong in individuals with kidney or liver disease, because the drugs remain in the body for an abnormally long time while these diseased organs slowly work to flush them from the body. What are the common side effects of beta blockers?Depending on the type of beta blocker prescribed, patients may experience one or more side effects, including:
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. It can also worsen the symptoms of patients who have an underactive thyroid (hypothyroidism). Therefore, all patients are encouraged to speak to their physician before making any changes in how they are taking beta blockers. What medications may interact with beta blockers?Patients should consult their physician before taking any other medication (either prescription or over-the-counter), nutritional supplements or herbal remedies. Of particular danger to individuals taking beta blockers are:
In some cases, physicians will prescribe other medications in combination with beta blockers, such as diuretics. Diuretics reduce the amount of fluid returned in the body by increasing urine flow and are often prescribed along with beta blockers to treat high blood pressure. Beta blocker and diuretic combinations will contain both names in the generic form of the medication. For example bisoprolol hydrochlorothiazide is a single tablet containing both bisoprolol (a beta blocker) and thiazide diuretics. What are the lifestyle considerations with beta blockers?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 to take their medication exactly as directed and to keep all scheduled follow-up appointments with their physician. Also, patients should take and record their blood pressure readings regularly, reporting anything unusual to their physician. Patients on beta blockers should measure their heart rate for a full minute periodically. If it is below 50 beats per minute or lower than normal, 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 the reaction of these allergies. What are the symptoms of beta blocker overdose?Symptoms of overdose can be similar to the medication’s side effects, but are usually more severe. Patients exhibiting any of these symptoms should contact their physicians immediately:
Can women take beta blockers during pregnancy?Use of beta blockers during pregnancy may cause low blood sugar, breathing problems, a slow heart rate, and low blood pressure in the newborn. 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 difficulty breathing 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 physician.
Can children take beta blockers?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.
Can the elderly take beta blockers?
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 aged patient’s ability to tolerate cool temperatures.
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