Beta-blockers are drugs that can lower stress on the heart and blood vessels. They can also help manage migraine, anxiety, tremor, and other conditions.
Other names for beta-blockers include beta-antagonists, beta-adrenergic blocking agents, and beta-adrenergic antagonists.
In this article, learn about the different types of beta-blockers, how they work, and who they can help.
Doctors mainly prescribe beta-blockers to manage cardiovascular symptoms, such as angina and high blood pressure.
Beta-blockers work by blocking the action of certain hormones in the nervous system, such as adrenaline. By doing this, they help prevent the activation of the “fight-or-flight” stress response.
Adrenaline and noradrenaline are hormones that prepare the muscles in the body for exertion. This is a crucial part of responding to danger.
If the body releases high levels of adrenaline, a person may experience a rapid heartbeat, high blood pressure, excessive sweating, anxiety, and heart palpitations.
Blocking the release of these hormones lowers stress on the heart and reduces the force of the contractions of the heart muscle. In turn, it also takes pressure off the blood vessels in the heart, the brain, and the rest of the body.
Beta-blockers also obstruct the production of angiotensin II, which is a hormone that the kidneys produce. This relaxes and widens the blood vessels, easing the flow of blood through them.
Beta-blockers have a range of uses. The sections below outline some of them.
The main use of beta-blockers is to manage cardiovascular symptoms.
They can help treat or prevent the following:
- congestive heart failure
- hypertension, or high blood pressure
- irregular heartbeat
- myocardial infarction, or heart attack
- a rapid heartbeat, or tachycardia
- coronary heart disease
In 2012, the American Academy of Neurology and American Headache Society recommended using propranolol and metoprolol, both of which are types of beta-blocker, as a first-line therapy for preventing migraine.
A 2019 review of trials from around the world concluded that propranolol was more effective than a placebo in preventing migraine and tension-type headaches.
Overall, the results suggested that this medication can reduce the number of episodes a person experiences from five to three per month.
Glaucoma is a condition in which pressure grows within the eye due to a buildup of fluid. It is a common cause of vision loss among older adults.
Doctors often prescribe eye drops containing beta-blockers to lower the production of this fluid and reduce pressure within the eye.
Beta-blockers block the effects of stress hormones. As a result, they can also reduce the physical symptoms of anxiety, such as trembling and sweating.
Although they do not have approval from the Food and Drug Administration (FDA) for treating anxiety, doctors may prescribe them off-label for this purpose.
However, beta-blockers cannot treat anxiety itself. Other treatments, such as counseling, can help address the underlying causes of anxiety.
Beta-blockers can reduce symptoms such as tremor and a rapid heart rate in people with an overactive thyroid.
They do this by blocking the action of thyroid hormone in the bloodstream.
Beta-blockers such as propranolol and primidone can help manage essential tremor.
Studies suggest that 50–60% of people see an improvement in symptoms when using propranolol, especially in hand tremor.
A doctor may recommend using this medication either as needed or all the time, depending on a person’s situation.
Beta-blockers help manage a range of conditions by blocking beta receptors, which occur throughout the body.
There are three types of beta receptor:
- beta-1 (B1) receptors, which occur mainly in the heart and regulate cardiac activity
- beta-2 (B2) receptors, which occur in various organs and play a role in smooth muscle relaxation and metabolic activity
- beta-3 (B3) receptors, which help break down fat cells
Current medical applications focus on B1 and B2 receptors.
Beta-blockers can also be selective or non-selective. Selective beta-blockers mostly target the heart, while non-selective ones manage symptoms in other parts of the body.
Here are some common types and brands of beta-blockers:
Beta-blockers affect receptors throughout the body and can have a range of side effects, including:
- slow heartbeat, or bradycardia
- low blood pressure
- cold feet and hands
- nausea and vomiting
- weakness and dizziness
- abdominal discomfort
- sleeping difficulties and disturbances
- erectile dysfunction
- memory loss
- fluid retention, or edema, which may occur when a person starts using carvedilol
There is also a risk of heart block, especially in people with heart disease.
People should advise their doctor if they have a history of any of the following before taking beta-blockers:
- asthma, though some types may be suitable
- severe peripheral artery disease, including Raynaud’s disease
- a slow heart rate
- uncontrolled heart failure
People with stable heart failure can use beta-blockers.
Those who have a heart condition or chest pain and a history of cocaine use should talk with their doctor before using beta-blockers. This is because there is some debate about whether or not it is safe to use them in these circumstances.
Some types of beta-blocker may be safe to use during pregnancy if a doctor advises it. The doctor can advise on which beta-blockers are suitable for an individual to use after considering their full medical history.
Like all drugs, beta-blockers can interact with a number of other medications. These include:
- anti-arrhythmics, for managing irregular heartbeats
- antihypertensives, which lower blood pressure
- antipsychotics, for treating severe mental health problems
- clonidine, for treating high blood pressure and migraine
- mefloquine, to treat or prevent malaria
Different beta-blockers can have different interactions. A pharmacist or doctor can advise on which medications each type of beta-blocker will interact with.
For this reason, it is essential for people to inform a doctor about any medications they are using, including over-the-counter drugs and supplements.
People should not suddenly stop taking beta-blockers without their doctor’s advice and close supervision.
Suddenly stopping beta-blocker treatment may worsen a person’s symptoms, especially after a heart attack or during the treatment of angina.
Beta-blockers are a first-line treatment for many conditions. They are especially useful for improving cardiovascular symptoms, such as high blood pressure.
People should always follow a doctor’s instructions when using beta-blockers, and they should ensure that their doctor knows about any health conditions they have or other medications they are using.