Beta blockers were first used in the 1960s to treat angina or chest pain related to stress or exertion, and they are still a primary treatment for multiple cardiac issues. Today, millions of Americans take a beta blocker daily. Modern research shows that this class of medication can also treat or prevent a variety of diseases beyond cardiac conditions.
How Do Beta Blockers Work?
Some cells in the body have small proteins on the outer surface. These beta receptors are one of three types. Beta-1 receptors are only on cardiac cells. Beta-2 receptors appear on cells in the lungs, blood vessels, and, to some extent, the heart. Beta-3 receptors are on fat cells. The nervous system releases chemicals — norepinephrine and adrenaline — that communicate with beta receptors to increase heart rate, constrict blood vessels, relax the airway, and stimulate the kidneys to release proteins that increase blood pressure. Beta blockers settle into these receptors, preventing the chemicals from binding and stopping these responses.
Nonselective Beta Blockers
Non-selective beta blockers are the earliest type. These medications work by blocking both beta-1 and beta-2 receptors, those on the heart, lungs, and blood vessels. Because these medications affect the respiratory system, they are generally not recommended for patients with chronic obstructive pulmonary disease or COPD. They’re also not recommended for people with asthma.
Cardioselective Beta Blockers
Cardioselective beta blockers block only the beta-1 receptors of the heart. This means that they are safe for patients with COPD and other lung disorders. Adverse effects are less common with this type of beta blocker. That said, they may not be as selective at high doses, when they can start to affect beta-2 receptors.
Third-Generation Beta Blockers
Third generation beta blockers block beta and alpha receptors, which helps relax the blood vessels. Studies show that third generation beta blockers have fewer adverse effects and benefit the patient more than conventional beta blockers. Possible benefits include decreasing bad cholesterol, increasing good cholesterol, and improving insulin resistance.
Precribing Beta Blockers
Beta blockers are only used as treatment for patients with high blood pressure if other medications have not been effective. They are a primary treatment to prevent, treat, or improve chest pain, heart attack, irregular heartbeat, and heart failure. Beta blockers can be used alone or in conjunction with other medications.
Beta Blockers Side Effects
Beta blockers affect various parts of the body. Luckily, they have been used in medicine for so long that doctors are well aware of most of their side effects. These can include fatigue, shortness of breath, dizziness, constipation, diarrhea, weight gain, reduced exercise tolerance, cold hands and feet, and mild depression. High doses can cause a drop in blood pressure and increase the risk of falling. The lower the dose, the lower the chance of side effects.
What Happens When You Stop Taking Beta Blockers?
If someone stops taking beta blockers suddenly, rebound phenomenon can occur. This means the patient’s condition may come back worse than it was before treatment, resulting in high blood pressure, angina, worsening of heart failure, and tachycardia or increased heart rate. Although rebound phenomenon is rare, it is important to teach patients about it and understand the signs because so many Americans take beta blockers every day. Always consult a doctor before stopping a beta blocker.
Re-Evaluation
People taking beta blockers require occasional re-evaluation, particularly if something in their health or physical exam results changes. This can help avoid rebounding and make sure the person is still taking the appropriate dose. People who experience adverse side effects should never stop taking a beta blocker unitl a physician teaches them how to safely wean themselves off the medication.
Beta Blockers and Cancer
Researchers are studying the potential of using beta blockers as anti-cancer drugs. Several studies are promising, indicating the medication may prevent and protect against certain types of cancer, including ovarian cancer, breast cancer, and multiple myeloma. The results of these studies are inconclusive and have some inconsistencies, but further research could uncover future possibilities for cancer treatment.
Beta Blockers For Other Conditions
Beta blockers are sometimes prescribed for off-label uses, which means a doctor will have their patient take them for a condition other than those they are approved to treat. Off-label can also refer to unapproved doses, age groups, or routes of administration. Some physicians prescribe beta blockers to treat migraines and performance anxiety. They are not an effective treatment for persistent anxiety.