- What Are Beta Blockers?
- How Do Beta Blockers Work?
- Common Beta Blockers
- Side Effects of Beta Blockers
- Beta Blocker Precautions
- Beta Blockers, Alcohol, and Caffeine
- Beta Blockers and Pregnancy
- Beta Blockers and Certain Populations
- Beta Blocker Basics
- Beta Blockers and Physical Activity
- Concerns About Exercising While on Beta Blockers
- I’m still worried, what do I do?
- Beta-Blockers for Heart Disease
- Beta Blockers: What They Are, What They Do & Side Effects
- What Do Beta Blockers Do?
- What Are Beta Blockers Side Effects?
- Selective vs. Nonselective Beta Blockers
- Learn More About Beta Blockers
- Beta-Blockers for Heart Problems
- Path to improved health
What Are Beta Blockers?
This important and widely used class of drugs treats several cardiovascular conditions.
Beta blockers are a group of medicines used to lower blood pressure.
They’re given to treat or prevent a variety of conditions, including:
- High blood pressure
- Irregular heartbeat
- Chest pain
- Congestive heart failure
- Heart attack
- Anxiety disorders
- Hyperthyroidism (overactive thyroid)
How Do Beta Blockers Work?
Beta blockers work by blocking the effects of the hormone adrenaline, also known as epinephrine.
They cause the heart to beat more slowly and with less force, which lowers blood pressure.
They also help open up blood vessels to improve blood flow.
Some types of beta blockers mainly affect the heart. Others affect both the heart and blood vessels.
Common Beta Blockers
Some commonly prescribed beta blockers include:
Side Effects of Beta Blockers
Common side effects of beta blockers include:
- Drowsiness or fatigue
- Cold hands and feet
- Dry mouth, skin, or eyes
- Upset stomach
- Diarrhea or constipation
Less common side effects include:
- Shortness of breath
- Wheezing or trouble breathing
- Loss of sex drive/erectile dysfunction (ED)
- Trouble sleeping
- Swelling of the hands or feet
- Slow heartbeat
- Skin rash
- Sore throat
- Memory loss or confusion
- Back or joint pain
Beta Blocker Precautions
If you have asthma or diabetes, talk to your doctor before taking a beta blocker.
These drugs may trigger a severe asthma attack and can mask signs of low blood sugar.
Let your doctor know about all other medical conditions you have before starting on a beta blocker.
Also, tell your doctor about all medicines you’re taking, especially:
- Other medications for high blood pressure
- Drugs for diabetes (including insulin)
- Medications for asthma, chronic bronchitis, emphysema, or chronic obstructive pulmonary disease (COPD)
- Allergy shots
- Antacids that contain aluminum
- Over-the-counter (OTC) cough, cold, or allergy medicines
Beta Blockers, Alcohol, and Caffeine
Avoid eating or drinking products that contain alcohol or caffeine, since these drugs can affect how beta blockers work in your body.
Beta Blockers and Pregnancy
Tell your doctor if you’re pregnant, or might become pregnant, while taking a beta blocker.
Some beta blockers may be safe to take during pregnancy, while others may be harmful. Discuss the risks and benefits of taking these drugs with your doctor.
Also, talk to your healthcare provider before taking a beta blocker if you’re breastfeeding.
Beta Blockers and Certain Populations
Beta blockers may not work as well in people of African descent as in other racial or ethnic groups. Discuss this potential effect with your doctor.
Older people tend to experience more unwanted side effects when taking beta blockers.
Talk to your doctor about this risk if you’re over age 60.
Beta blockers are a type of cardiac medication prescribed after a heart attack or to treat abnormal heart rhythms (arrhythmias) and other conditions. They slow down your heartbeat, and that raises a common question about them: Do they affect your ability to exercise?
The answer can vary a great deal, depending on the severity of your condition, so checking with your healthcare provider is vital. It’s also important to understand how these drugs affect your heart.
Beta Blocker Basics
Beta blockers relieve stress on your heart by slowing the heartbeat. This decreases the force with which the heart muscle contracts and reduces blood vessel contraction in the heart, brain and throughout the body. They are prescribed under several common brand names, including Propranolol (Inderal), Metoprolol (Lopressor), Atenolol (Tenormin) Acebutolol (Sectral), Bisoprolol (Zebeta) and Nadolol (Corgard).
Beta blockers may be used to treat abnormal heart rhythms and to prevent abnormally fast heart rates called tachycardia, or irregular rhythms like atrial fibrillation. Since they reduce the demand of the heart muscle for oxygen, they may be useful in treating angina, or chest pain, which occurs when the oxygen demand of the heart exceeds the supply. Beta blockers improve survival after a heart attack and also are used to treat high blood pressure and other heart conditions.
Beta Blockers and Physical Activity
Interestingly, beta blockers and exercise have some similar effects on the body.
“Your blood pressure and heart rate are similarly changed by exercise and beta blockers,” said Gerald Fletcher, M.D., Professor of Medicine at the Mayo Clinic in Jacksonville, Florida. “When you become exercise-trained your heart slows and your blood pressure lowers.”
Of course, that doesn’t mean you can take beta blockers in lieu of exercise. Exercise has many other benefits and is important to maintain your health. Read how physical activity improves the quality of life.
Concerns About Exercising While on Beta Blockers
“It’s important to remember that your heart rate is being slowed, and to adjust accordingly if before you took these drugs you monitored your exercise using heart rate,” said Dr. Fletcher, who is also a volunteer with the American Heart Association.
“Don’t overdo it trying to get your heart rate up to previous levels,” he said.
There are a couple of ways to monitor your exercise intensity.
- If you have been using a target heart rate to get to the right intensity, your healthcare provider can help to determine your new target heart rate using a brief exercise stress test . This test is used because beta blockers affect everyone differently.
- The second way to monitor your intensity is simpler: making sure you’re not too exhausted.
“Exercise hard – to the point of being tired – but not excessively hard,” Dr. Fletcher said. “If you reach a point where it is hard to talk, that is probably too much.”
I’m still worried, what do I do?
It is important to know you are taking these medications for a specific reason. But if you are still concerned, talk to your healthcare provider. He or she may prescribe a different beta blocker or another medication that has less of an effect on heart rate.
Beta-Blockers for Heart Disease
People with asthma typically shouldn’t take beta-blockers since they can trigger asthma attacks.
Because beta-blockers may affect the control of blood sugar, they’re not usually recommended for people with diabetes.
Side effects of these medications can vary. Many people will experience:
- cold hands
- digestive problems
Rarely, you may experience:
- shortness of breath
- trouble sleeping
- decreased libido
If you accidentally take a larger dose than recommended, you may experience:
- difficulty breathing
- changes in vision
- irregular heartbeats
If you know that an overdose has occurred, call your doctor or local poison control center. The U.S. National Poison Control Center phone number is 800-222-1222.
Some of the older beta-blockers — such as atenolol and metoprolol — have been reported to cause an average weight gain of 2.6 pounds, according to the Mayo Clinic. Fluid retention and accompanying weight gain can be signs that you have heart failure or that your heart failure is getting worse. Be sure to let your doctor know if you gain more than 2 to 3 pounds within a day, gain more than 5 pounds within a week, or your symptoms worsen.
You also may notice some changes in the way your heart works during day-to-day life. For example, beta-blockers prevent spikes in heart rate. You may notice that your heart rate doesn’t climb as high as it normally would during exercise.
Speak with your doctor if you’re concerned about your workouts while taking this medication. They may recommend a stress test to determine your target heart rate during cardio. Stress tests can also help your doctor determine how hard you feel you’re working during a workout. This is known as the rate of perceived exertion.
Beta-blockers were one of the first modern medications used for the treatment of blood pressure. Before 1950, treatment options for hypertension were limited. The alphabet soup of medications — reserpine, pentaquine, hydralazine, and guanethidine — were notorious for inducing orthostasis, sedation, constipation, impotence, or blurry vision. Then in the 1960s, propranolol and chlorothiazide were developed. Initially designed to treat angina pectoris, propranolol was serendipitously discovered to also lower blood pressure. Oddly, propranolol, like the other beta-blockers in its generation and thereafter, did not act directly on the blood vessel to lower blood pressure. Instead, its purported mechanism of action was via inhibition of beta-adrenergic receptors, reduction of cardiac output, and decrease in sympathetic outflow.
Despite beta-blockers’ odd mechanism of action, they were (and still are) as effective as the earlier anti-hypertensive agents in decreasing blood pressure. Beta-blockers became extremely popular once they were found to have many fewer side effects than the older generation of drugs. Since then, many derivatives and generations of the beta-blocker have come into use and have become the mainstay in the treatment of hypertension. In the subsequent 40 years, beta-blockers battled high blood pressure in the front lines.
But in 2014, researchers appointed to the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC) released what was called the 8th guideline on treating hypertension. In these new recommendations, beta-blockers were relegated to second-line treatment, behind thiazide diuretics, calcium channel blockers (CCB), angiotensin-converting enzyme inhibitors (ACEi), and angiotensin II receptor blockers (ARBs). After being the crux of hypertension treatment for decades, are beta-blockers becoming obsolete?
Several studies from the early 2000s rendered the beta-blocker a less attractive treatment option for hypertension. In 2002, rallying more than 30,000 hypertensive individuals, the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) showed that treatment with the thiazide diuretic chlorthalidone decreased the rate of heart failure (HF) significantly more than an ACEi and a CCB. Additionally, African Americans treated with chlorthalidone were less likely to have a stroke. A smaller trial published around the same time, Intervention as a Goal in Hypertension Treatment (INSIGHT), also showed a reduction in HF rates. In contrast, these outcomes have not been demonstrated with beta-blockers. Thus, ALLHAT and INSIGHT brought thiazide diuretics to the forefront of hypertension treatment.
A second hit befell beta-blockers in 2004, when a meta-analysis published in The Lancet suggested that atenolol did worse than other hypertension medications in reducing the risk of stroke (relative risk 1.13; 95% CI 1.02-1.25). Subsequent studies and larger meta-analyses confirmed this relationship, and exposed propranolol as also having this deficiency. Based on the mounting evidence, the JNC-8 guidelines relegated beta-blockers to second-line therapy for high blood pressure.
Several theories have been proposed to explain this observed risk of stroke. One theory that is gaining strength is based on the idea of pulse wave dyssynchrony, whereby pressure waves are prematurely reflected back from the periphery by older and stiffer arteries, resulting in increased central systolic pressures. Because beta-blockers increase the length of systole, they exacerbate pulse wave dyssynchrony thereby increasing central aortic pressures. Using pressure sensors designed to calculate central pressures from the radial artery (called radial artery applanation tonometry), one study showed that not only did higher central aortic pressures lead to worse cardiovascular outcomes, but that beta-blockers were less capable of lowering central blood pressure when compared to CCBs. Atenolol, in particular, could further worsen this dyssynchrony by causing relative peripheral vasoconstriction.
Keep in mind, however, that not all beta-blockers are created equal. For instance, the newer generation of beta-blockers has shed many of the older agents’ undesirable side effects, including the hyperglycemia and hyperlipidemia of the first and second generations. Moreover, beta-blockers like carvedilol and nebivolol appear to decrease peripheral vascular resistance either through alpha-1 blockade or by promoting nitric oxide (NO) release, respectively, rather than by reducing the cardiac output. These well-publicized mechanisms translated to modest reductions in central aortic pressure when compared to atenolol in small studies. Several clinical trials are already underway to study the blood pressure lowering effects of third-generation beta-blockers. However, further studies will be needed to examine the long-term effects of the newer beta-blockers and how they influence stroke risk, coronary heart disease outcomes, or overall mortality in uncomplicated hypertension.
Despite all the shortcomings of the beta-blocker, it is not yet time to give up on our old friend. A recent Cochrane Review showed that when compared to placebo, beta-blockers have a modest effect on decreasing the risk of stroke (RR 0.80; 95% CI 0.66-0.96). Additionally, a meta-analysis in 2007 showed that most of the previously observed stroke risk was confounded by older populations. The authors were able to show that this risk between beta-blockers and other antihypertensive agents was eliminated when the analysis focused on patients under 60 years old. Furthermore, most of the analyses on cardiovascular outcomes of beta-blockers were derived from studies using atenolol and propranolol and may not apply to other agents in the family. For instance, the Metoprolol Atherosclerosis Prevention in Hypertensives (MAPHY) study showed that there could be a reduction in stroke and coronary heart disease when using a long-acting beta-blocker, such as metoprolol succinate. Finally, newer agents in the class with fewer metabolic side effects may become standard in our armamentarium to treat hypertension in the future. There are reasons why our counterparts up north still recommend beta-blockers as first-line therapy for younger patients and why they are still an appropriate option for treatment, especially in resistant hypertension.
Robin Guo, MD, is an internal medicine resident at NYU Langone Medical Center. A version of this article first appeared at Clinical Correlations, The NYU Langone Online Journal of Medicine. Full citations are available at the original post.
Beta Blockers: What They Are, What They Do & Side Effects
When you’re in a stressful or tense situation, your body has a natural fight-or-flight response that causes your heart to beat faster than normal. Beta blockers are a class of medications that prevent the stress hormones that contribute to your body’s fight-or-flight response from affecting your heart.
Most beta blockers are designed to treat heart conditions, such as high blood pressure, an irregular heartbeat or a high risk of heart attack. They’re also used to treat anxiety disorders, hyperthyroidism, tremors and diseases like glaucoma.
Below, we’ve explained what beta blockers are in more detail, as well as what they do to your body when you use them. We’ve also explained how beta blockers can be useful for treating anxiety and calming your nerves in tough, stressful situations.
Also known as beta-adrenergic blocking agents, beta blockers are medications that block the effects of adrenaline, or epinephrine, on your heart, as well as other stress hormones such as noradrenaline.
Adrenaline and noradrenaline are used by your body to activate your fight-or-flight mechanism, which is designed to protect you in a dangerous situation.
Normally, being in a stressful situation causes your body to secrete more adrenaline, resulting in a noticeably faster heartbeat. You might also notice your hands becoming shaky and sweaty, as well as your voice becoming shaky and faint.
Many people also experience dizziness—another physical effect of an increase in your body’s adrenaline levels. This increase in adrenaline and its noticeable effects can cause you to panic when under pressure.
Beta blockers reduce the effects of adrenaline on your heart, making it easier for your heart to relax in the presence of stress hormones. Instead of a fast heartbeat, your heart will beat at a normal pace, limiting the physical effects of adrenaline on your body.
There are numerous beta blocker medications available. Most beta blockers target the heart specifically, while others also reduce your body’s secretion of angiotensin, a hormone that can restrict your blood vessels.
What Do Beta Blockers Do?
Beta blockers are used to treat several different conditions. Most beta blockers were designed to treat heart conditions such as high blood pressure and irregular heartbeat (atrial fibrillation), both of which can contribute to excessive stress on the heart.
By reducing the amount of stress on the heart muscles, beta blockers can make heart attacks and other major health issues less likely.
Many doctors also prescribe beta blockers for anxiety. By blocking the effects of stress hormones like adrenaline on your heart, beta blockers can block the physical effects of anxiety on your body, such as sweating, a rapid heartbeat or dizziness.
When using beta blockers for anxiety, It’s important to understand they don’t treat the psychological causes of anxiety itself. Instead, they just make it easier for you to handle the physical reaction your body might have to feelings of anxiety.
Some beta blockers are also used to treat hyperthyroidism, which can contribute to excessive weight loss, tremors, sleep issues, nervousness and other symptoms.
Beyond treating heart conditions and reducing the physical effects of anxiety, beta blockers may also have other health benefits. For example, some beta blockers are linked to reduced levels of bone mineral loss in people at high risk for osteoporosis and bone resorption.
Beta blockers have been in use since the 1960s, but today, there are several beta blockers on the market, many of which are actively used as treatments for heart and anxiety conditions. Some of the most widely used beta blockers include:
What Are Beta Blockers Side Effects?
Like almost all medications, beta blockers can have side effects. Most of the beta blockers side effects of beta blockers are fairly mild. It’s also possible for beta blockers to interact with other medications and cause more severe, serious side effects.
The vast majority of people who use beta blockers do not experience side effects. Overall, beta blockers are safe and very effective, with a low risk of side effects when used according to your doctor’s instructions.
The most common side effects of beta blockers are:
- Fatigue. Because beta blockers cause your heart rate to decrease, it’s common to feel a slight reduction in energy. Some people who use beta blockers feel fatigued after starting treatment due to the effects of the medication on the heart.
If you feel fatigued after using a beta blocker, it’s best to talk to your doctor. Most of the time, this side effect can be avoided by adjusting your dosage or using a different type of beta blocker medication.
- Weight gain. Some beta blockers, particularly older medications such as metoprolol and atenolol, can contribute to weight gain. While there’s no consensus on why this happens, it’s believed to be linked to fluid retention or the medication’s effects on your metabolism.
Most of the time, weight gain from beta blockers is fairly mild. Expect to gain one or two pounds, if anything. This weight gain can often be reversed by switching to a newer beta blocker.
- Cold feet and hands. Beta blockers can potentially make your hands and feet feel cold as a result of their impact on your blood circulation. Like many other side effects of beta blockers, this can often be avoided by adjusting your dosage or changing medications.
- Nausea, dizziness and lightheadedness. It’s fairly common to feel slightly dizzy and lightheaded after using beta blockers, especially the first few times. This side effect is usually temporary and tends to disappear after using beta blockers for several days.
There are also several less common side effects of beta blockers. These include:
- Slow heartbeat. Beta blockers are designed to relieve cardiovascular stress by giving you a slower heartbeat. If you take too large a dose of your beta blocker medication, it’s possible to experience bradycardia, or an unusually slow heart beat.
If your resting heart rate while awake is under 50 beats per minute after you take a beta blocker, contact your doctor. This side effect is most common if you use calcium channel blockers at the same time as beta blockers to treat hypertension.
- Higher cholesterol and triglyceride levels. Some beta blockers can cause a reduction in your high-density lipoprotein (HDL, or “good cholesterol”) levels, as well as increases in triglycerides.
This side effect is often temporary and can reverse over time. Overall, beta blockers are effective at treating heart conditions and shouldn’t be avoided because of the potential for changes in your cholesterol levels.
- Asthma attacks. Although the science isn’t completely settled here, some beta blockers are linked to an increased risk of asthma attacks in people with severe asthma.
This side effect is most frequently documented with older medications. It’s less common with newer beta blockers, the majority of which are safe for people with mild to moderate asthma.
- Cramps. Although it’s uncommon, some people experience cramps—particularly in the abdominals—while using beta blockers.
- Depression. Like asthma attacks, the science on beta blockers and depression isn’t completely settled. A small percentage of people who use beta blockers experience depression and memory loss, although this may not be caused by the medication.
Because beta blockers affect your heart rate, they can also affect your life in ways unrelated to anxiety and heart issues:
- Interaction with stimulants. It’s recommended to avoid stimulants such as caffeine while using beta blockers, as caffeine can increase your heart rate, anxiety symptoms and blood pressure, countering the effects of beta blocker medications.
- Effects on exercise. After taking a beta blocker, your maximum heart rate will be lower than normal. This means you might have less stamina while exercising, especially if you do cardiovascular exercises such as running, cycling, walking or rowing.
- Consumption of high-sodium foods. Eating foods that are high in sodium, such as fast food, can raise your blood pressure and put extra pressure on your heart. If you’re prescribed a beta blocker for heart issues, it’s best to avoid eating high-sodium foods.
- Consumption of high-potassium foods. Because beta blockers affect your body’s ability to process potassium, it’s also recommended to avoid potassium-rich foods if you’re prescribed a beta blocker for heart issues or anxiety.
Overall, beta blockers are a safe, reliable and effective medication. Most people who take beta blockers experience few or no side effects, especially with the newer medications used today.
Selective vs. Nonselective Beta Blockers
There are two main types of beta blocker medication: selective beta blockers and nonselective beta blockers.
Selective beta blockers are designed specifically to block the β1 receptors, which are primarily located in the heart. Because the action of these beta blockers is more specific, they’re usually safe for use if you have diabetes.
Common selective beta blockers include acebutolol, atenolol, bisoprolol, betaxolol, bevantolol, celiprolol, metoprolol, esmolol and nebivolol.
Because selective beta blockers only affect the β1 receptors, which are concentrated in heart tissue, they tend to be used to treat heart conditions and aren’t a popular treatment option for anxiety.
Nonselective beta blockers are designed to block the β1, β2 and β3 receptors. This means that as well as targeting beta receptors in the heart, they also affect the veins, liver, pancreas and a range of other parts of the body.
Common nonselective beta blockers include alprenolol, carteolol, oxprenolol, propranolol and sotalol. As well as being used to treat certain heart conditions, nonselective beta blockers can be used to treat some physical effects of anxiety.
Unlike selective beta blockers, nonselective beta blockers are not considered safe to use if you have diabetes.
Learn More About Beta Blockers
Beta blockers are some of the most widely used medications in the world, prescribed for heart conditions, anxiety and more. Safe, easy to use and effective, they provide fast and noticeable results that make them ideal for preventing chronic anxiety and panic attacks.
Our guide to propranolol goes into more detail on how one of the most widely used beta blocker medications works, from its history to major benefits, potential side effects, drug interactions and more.
Beta-Blockers for Heart Problems
Path to improved health
You should take beta blockers exactly as your doctor tells you. Beta blockers often are taken 1 to 2 times a day. Try to take the medicine at the same time each day. Do not stop taking beta blockers without talking to your doctor first. If you missed a dose and realize it a few hours later, take the medicine right away. If it has been more than 4 to 6 hours, do not take the dose you missed. Instead, wait to take the next scheduled dose. Never take a double dose to catch up.
People who have certain health conditions need to be careful taking beta blockers. If you have diabetes, the medicine can hide warning signs of low blood sugar. For example, your heart rate may not increase normally in response to a low blood sugar level. You will need to check your blood sugar levels carefully when taking a beta blocker. Talk to your doctor if you often have low blood sugar. He or she may want to change the dosage of your diabetes medicine.
Beta blockers can be a problem for people who have asthma. They can cause asthma attacks. Work with your doctor to monitor your asthma and prevent attacks.
People who have a chronic lung disease, such as bronchitis, emphysema, or both diseases together, known as chronic obstructive pulmonary disease (COPD), can take beta blockers. However, you should call your doctor right away if you start having breathing problems.
Beta blockers may interact with other medicines. This includes over-the-counter medicines and prescriptions. The interaction can cause severe health problems. Tell your doctor about all medicines that you take. Check with your doctor before starting any new medicine.