Beta blockers have many benefits reducing cardiac symptoms in patients with hyperthroidism, and reducing anxiety and panic attacks in neuropsychological disorders.
Beta adrenergic blocking agents, which are commonly referred to as beta blockers, are a class of medications that block the effects of adrenaline and similar stimulating substances. Beta blockers occupy the beta cell receptor, blocking the response of certain nerve impulses. In autoimmune disease patients, beta blockers play an important role in reducing symptoms in patients with hyperthyroidism , migraine headaches, hypertension and arrhythmias (abnormal heart rhythms). Beta blockers also reduce the risk of heart attack and stroke in people with systemic lupus and other disorders who may have a higher risk for stroke.
Types of beta blockers
There are two subtypes of beta receptors: beta 1 and beta 2 receptors. Some of the newer beta blockers only block impulses for beta 1 receptors, which are usually found in the heart. These beta blockers, such as atenolol (Tenormin) are said to be cardioselective.
Beta 2 blockers affect the nerve impulses of beta 2 receptors which are found in smooth muscles. Beta 2 blockers such as propranolol (Inderal) can reduce pulmonary (lung) function and are not to be used in patients with asthma or respiratory disorders.
Effects and Uses of beta blockers
Besides their ability to block the beta receptor and reduce heart rate and blood pressure, beta blockers can reduce symptoms of anxiety and they block impulses that can lead to arrhythmia. Beta blockers may also decrease the sympathetic nervous system’s outflow and suppress the hormone renin, a substance elevated in hypertension. In addition, beta blockers are suspected of having antioxidant and cholesterol lowering properties.
Beta blockers are also used to prevent vascular headache and to reduce symptoms in pheochromocytoma a disorder with symptoms similar to those of hyperthyroidism. Other uses include to help prevent glaucoma
Potentially Adverse Side Effects
Some people are allergic or intolerant to beta blockers. For this reason, beta blockers should be started slowly, using a low dosing and watching for side effects before increasing the dose. Beta blockers can also cause the heart rate to fall too low causing a condition of bradycardia (unusually slow heartbeat). In general, beta blockers should not be used at a dose that causes the heart rate to fall below 60 beats/minute.
Depression can be increased by beta blockers. In addition, beta blockers cause a reduction in coenzyme Q10 that can contribute to depression and muscle pain. Because beta blockers can react adversely with other medications it’s important to check with your pharmacist. He or she can advise you on potential adverse drug interactions.
Beta blockers should only be used in pregnancy and in nursing mothers when the benefits of doing so outweigh potential risks, which include low blood sugar, breathing problems, decreased heart rate and blood pressure.
Common Side Effects
Common side effects include cold hands and feet, drowsiness, fatigue, dry mouth, eye dryness , dry skin, weakness, dizziness, slow heartbeat.
Less Common and Rare Side effects
Less commonly seen are swelling of the hands and feet. Trouble sleeping, vivid dreams, shortness of breath, wheezing, abdominal cramps, joint pain, depression and constipation.
Precautions
People with breathing problems or severe allergies should only use cardio selective beta blockers and then they should be used with caution. While controlling cardiac symptoms in hyperthyroidism, beta blockers also mask symptoms. In uncontrolled hyperthyroidism, beta blockers should never be stopped abruptly. Instead, the dose should be tapered or reduced slowly. Beta blockers can also mask the symptoms of low blood sugar (hypoglycemia) and should be used in caution in patients with diabetes or hypoglycemia.
Resources:
