What are beta blockers?
The class of drugs called beta blockers were given their name because this class of medications counteracts the stimulatory effects of epinephrine (adrenaline) on the so-called beta-adrenergic receptors found in many body tissues, including the nervous system and heart. Normal stimulation of the beta receptors leads to a faster heartbeat along with the constriction of blood vessels, resulting in an overall increase in blood pressure.
Beta blockers, therefore, counteract stimuli that lead to an elevated blood pressure, resulting in a slower pulse rate and a reduction in blood pressure. Both these effects reduce the workload of the heart, so beta blockers are of value in treating the symptoms of angina pectoris, the chest pain brought on by narrowing of the coronary arteries that causes inadequate delivery of oxygen-rich blood to the heart muscle. Beta blockers also are prescribed as treatments for high blood pressure and have been shown to improve survival when administered following a heart attack.
What are examples of beta blockers?
There are many different beta blockers available. Some examples of common beta blockers include:
What conditions are beta blockers prescribed to treat?
Beta blockers can slow the passage of impulses through the heart, so they can also be valuable drugs for the management of cardiac arrhythmias (disruptions in the normal rhythm of the heart beat). Beta blockers have also been used in the treatment of the following conditions:
- social anxiety,
- some kinds of tremors, and
- in certain cases of mitral valve prolapse.
What are the side effects of beta blockers?
Drowsiness, fatigue, dizziness, and weakness are the most common side effects reported by patients who take beta blockers. Other side effects that may occur are dry mouth and eyes, dry skin, diarrhea, nausea and vomiting, and feelings of coldness in the hands and feet. Less commonly, a decreased sex drive, shortness of breath, and sleep disturbances have been reported. Beta blockers are typically not prescribed for people suffering from asthma due to their potential for triggering an asthma attack. In people with diabetes, they can sometimes mask the symptoms of low blood sugar levels.
Robert J. Bryg, MD
Board Certified Internal Medicine with subspecialty in Cardiovascular Disease