What is a Beta Blocker

Beta blocker is a drug that blocks a beta receptor. A beta blocker is mainly used to treat a class of heart diseases. Before knowing what beta blocker is, and how it can block beta receptor, let us first understand what beta receptor is.

What is Beta Receptor?

Beta receptor is typical a protein molecule that processes messages generated by the nervous system and hormones. A beta receptor is located almost everywhere in the body, but is found mostly in blood vessels, heart and brain. A beta receptor can be of three types, namely, beta 1, beta 2 and beta 3.

Type of Beta Receptor	Location
Beta 1	Heart, Kidneys, Eyes
Beta 2	Lungs, Liver, Blood vessels, Uterus, Gastrointestinal tract, Skeletal muscles
Beta 3	Fat cells

What Stimulates Beta Receptor?

Epinephrine (adrenaline) and norepinephrine play a dual role of being a hormone and a neurotransmitter (chemical that modulates, amplifies and relays signals between a cell and a neuron). Though, these hormones are useful to the body, they are harmful when they are over-secreted. Both these hormones are released excessively, when the body faces "fight or flight" condition. Epinephrine stimulates all beta receptors; while norepinephrine stimulates only beta 1 and beta 3 receptors. Stimulation of beta receptors leads to increase in heartbeats and blood pressure, and constriction of blood vessels. These, in turn, result in heart disorders like arteriosclerosis, inadequate oxygen supply to heart, chest pain (angina) and arrhythmia.

What is a Beta Blocker and How does a Beta Blocker Work?

Beta blocker is a drug that blocks, or prevents the stimulation of a beta receptor. Thus, it creates an interference between the receptor and the stimulating hormone. It helps to widen the constricted blood vessels and reduces the increased heartbeat and blood pressure.

What are the Types of Beta Blocker?

For different beta receptors, there are different beta blockers. Selective beta blockers and non-selective beta blockers are two main categories of beta blockers. Non-selective beta blockers block beta 1 and beta 2 receptors; while, selective beta blockers, also called as cardioselective beta blockers, block only beta 1 receptors.

What are the Conditions Treated by Beta Blocker?

Doctors prescribe a beta blocker for patients suffering from angina, high blood pressure, arrhythmia, etc. A beta blocker is also used for prevention of heart attack (if an individual has already had one earlier) and migraine. It is also useful in treating eye diseases, like glaucoma, where the pressure in the eye increases suddenly. Treatment for akathisia, hyperthyroidism, anxiety, also include the use of beta blockers.

Name	Type of Beta Blocker	Disease Treated
Alprenolol	Non-selective	Angina pectoris
Carteolol	Non-selective	Glaucoma
Levobunolol	Non-selective	Glaucoma
Metipranolol	Non-selective	Glaucoma
Nadolol	Non-selective	High blood pressure, Migraine, Chest pain
Oxprenolol	Non-selective	Angina pectoris, Arrhythmia
Acebutolol	Selective	Hypertension, Arrhythmia
Atenolol	Selective	Cardiovascular diseases
Betaxolol	Selective	Hypertension, Glaucoma
Metoprolol	Selective	Hypertension

What are the Side Effects of Beta Blocker?

Like every medication, beta blocker also has side effects. Many a times, it happens that the side effects of beta blocker are similar to symptoms of heart disorders. It is still unclear, if the side effects are due to beta blocker or because of the patient's disease. A list of probable health consequences is given below:

• Reduced heartbeat
• Low blood pressure
• Asthma
• Dizziness
• Cramps in muscle
• Nausea
• Headache
• Constipation
• Breathing difficulty
• Diarrhea

Small doses of beta blocker are usually not harmful. People with sinus bradycardia, partial AV block and asthma are not advised to use beta blocker. Diabetic patients are recommended to use beta blocker cautiously, as it may have adverse side effects. The side-effects may vary from person to person. However, it's not that every person who takes beta blocker will show side effects.

Beta blocker should always be taken, in accordance to a doctor's prescription. Beta blocker has proved to be useful in treating many heart problems. However, doctors prescribe it with caution, due to the side effects. Beta blocker can be used to treat patients, who have mild heart problems. Though, beta blocker therapy is not a cure for heart problems, it can help reduce its effect.