Heart disease kills one in every four people in the United States. And about 70 percent of people 65 and older take heart medications, according to the Centers for Disease Control and Prevention.
Some of the most commonly prescribed medications for heart problems are beta blockers, which help conditions such as chest pain, high blood pressure and irregular heartbeat. Doctors say beta blockers are a critical tool for managing symptoms, as well as for preventing a second heart attack after a patient has had a first one. “It is our go-to medication for people who have a real heart problem,” says Dr. Mouin Abdallah, a cardiologist at Cleveland Clinic, adding that more than half of his patients are on beta blockers.
Here’s what to know about the medication, which was invented by a researcher grieving his father’s death from a heart attack.
[See: The Facts on Heart Disease.]
Labor of love
In the early 1960s, Scottish pharmacologist Sir James W. Black developed the first beta blocker, propranolol, after studying the effects of adrenaline on the heart. He became interested in the topic as a young medical student when his father died suddenly from a heart attack after a minor car crash, he wrote in the British Journal of Pharmacology in 2010. Black believed that his father’s heart attack was brought on by an adrenaline rush, so he dedicated himself to inventing a medicine that relaxes the heart. Black was awarded the Nobel Prize in Medicine in 1988 in part for this breakthrough medicine (he also developed the medicine cimetidine, which is used to treat stomach ulcers).
In the five-plus decades since Black developed beta blockers, doctors have consistently used the drugs to combat heart disease and its symptoms. A study published in BMC Cardiovascular Disorders in 2013 analyzed 30 trials of nearly 25,000 patients comparing people who were given beta blockers with those given a placebo. It found that beta blockers reduced the risk of sudden cardiac death such as a heart attack by 31 percent, death from other cardiovascular causes by 29 percent and all-cause mortality by 33 percent.
“With beta blockers, angina gets better, heart rhythm feels better,” Abdallah says. “The vast majority of people feel better with beta blockers.”
How do they work?
When the heart’s arteries become narrowed from coronary disease or when the heart becomes weakened from such conditions as heart failure, the heart compensates by pumping harder and faster. This increases the demand for oxygen and can cause a condition called angina, which is chest pain, as well as problems such as high blood pressure or arrhythmia, which is an irregular heartbeat.
Beta blockers slow down the heart to give it a break from working so hard. The heart’s squeezing function relaxes a bit, which causes blood pressure to go down, easing pain and helping regulate the heartbeat.
Beta blockers function by muting the effects of adrenaline, the hormone that causes the heart to pump faster, says Dr. Blanding Jones, a cardiovascular surgeon at Kaiser Permanente Los Angeles Medical Center. “Adrenaline is very useful in fight-or-flight situations if you’re scared or threatened, or in a sporting or competitive event. People feel revved up, they feel their heart pounding,” Jones says. “It will make you perform at your best to compete, or save your life, if you look at the anthropological reasons for such a response in times of stress.”
But for people with heart problems, adrenaline can be problematic. “More adrenaline is circulating because the cardiovascular system senses stress related to the heart condition,” Jones says.
Beta blockers reduce the effects of adrenaline by interfering with beta receptors, located in the heart and elsewhere, that bind to hormones like adrenaline. Less adrenaline response means a slower, more predictable heartbeat.
“Beta blockers can affect the rhythm of the heart by slowing it,” Jones says. “If the heart is irritable for any reason, they can decrease the stimulation to the heart.”
[See: The 12 Best Heart-Healthy Diets.]
Evolution of beta blockers
Beta blockers have become more targeted over the decades. The initial beta blockers were “non-selective,” meaning they blocked adrenaline receptors in the heart, as well as other organs such as kidneys, lungs and liver. Later beta blockers were more sophisticated and able, for example, to target only adrenaline receptors in the heart.
There are now more than a dozen beta blockers, all ending in “lol.” These include atenolol, metoprolol and betaxolol.
The most effective way to prescribe beta blockers, experts agree, is to start at a low dose and gradually increase the prescription every two to four weeks to reach the target dose, making sure a condition called bradycardia, or slow heartbeat, doesn’t develop, according to the Cleveland Clinic. Likewise, if a patient is going to stop taking the medication, he or she needs to wean off it, or risk pain or even heart attack.
Risks
That’s not the only risk associated with the medicine. When patients are prescribed beta blockers for a heart condition, they generally take them for the rest of their lives unless they’re unable to tolerate them. Possible side effects include tiredness, dizziness and generally feeling unwell, Abdallah says. Not everyone experiences those side effects, but if a patient does, it can pose a quandary for doctors because heart problems are also liable to cause tiredness.
“Sometimes it’s hard to know how much fatigue is due to their primary heart problem or side effects from the beta blockers,” Abdallah says. “Usually we’ll adjust the medications and see if the side effects go away with time.”
There are additional risks for patients with lung problems. Those with asthma or chronic obstructive pulmonary disease, for example, should be careful with beta blockers because they can cause the lungs to constrict and inhibit breathing. A report published in the Cleveland Clinic Journal of Medicine in 2010 found that such patients can take beta blockers as long as they’re the kind that target only the heart’s adrenaline receptors.
Doctors are also careful when they prescribe beta blockers to patients with severe diabetes because it can mask signs of low blood sugar, Jones says. Additionally, he says, patients with slow heart rate or low blood pressure aren’t prescribed beta blockers.
[See: 6 Signs You’re Having a Heart Attack.]
Alternate uses
Doctors have discovered some uses for beta blockers that don’t involve the heart. Psychiatrists prescribe it to reduce anxiety and stress, for example; the idea is that blocking adrenaline calms the heart as well as the mind.
A report published in 2015 in the journal Biological Psychiatry found that beta blockers were effective in helping people overcome phobias, and even showed that arachnophobes who took beta blockers became comfortable enough to actually touch spiders. Beta blockers are sometimes used for migraines and thyroid conditions, as well as some other disorders that involve hormones.
“It is one of the most commonly used drugs by cardiologists for sure,” Abdallah says. “If it works for other uses and is prescribed by a doctor, that seems appropriate.”
More from U.S. News
How to Avoid a Second Heart Attack
The 12 Best Heart-Healthy Diets
6 Drugs That Can Worsen or Increase Risk for Heart Failure
What to Know About Beta Blockers originally appeared on usnews.com
