Beta blockers (beta-adrenergic blocking agents or beta-adrenergic antagonists) are drugs which were initially used for treating hypertension and heart conditions for example cardiac arrhythmia and heart attack. Over the years, medical research has revealed their ability to alleviate the symptoms of other medical conditions such as atrial fibrillation, angina, accelerated heart rate, heart failure, anxiety and glaucoma. In this article, we will look into the mechanism of action of beta blockers inside the treatment of some of these diseases. Scroll down to learn how these drugs assist in treating various medical conditions.
Connection between Beta Blockers and Beta Receptors
If you go by means of beta blockers list, you are going to locate that these heterogeneous group of beta-adrenergic blocking agents are classified on the basis of the beta receptors they block. Beta receptors, which fall under the category of adrenergic receptors, are receptors that are found on the surface of cells of some organs or tissues. Beta-receptors are classified into beta-1, beta-2 and beta-3 receptors. Beta-1 receptors could be found inside the eyes, kidneys as well as the heart and beta-2 receptors are located in the liver, lungs, blood vessels, smooth vascular muscles and gastrointestinal tract. Beta-3 receptors may be found inside the adipose tissue. When these are targeted by adrenergic substances including epinephrine or norepinephrine, certain physiologic responses take place. It’s the stimulation of the beta-receptors by epinephrine and norepinephrine that provides rise to the flight or fight response. An accelerated heart rate, rapid heartbeat or increase in high blood pressure that’s experienced when we feel intense fear is caused due to the stimulation of beta-receptors. Since beta blockers prevent norepinephrine and epinephrine from binding to these receptors, such physiologic responses could be averted.
Mechanism of Action of Beta Blockers
The term ‘mechanism of action’ is utilised with reference to the specific biochemical interaction that helps a drug produce its pharmacological effect. The mechanism of action of beta blockers involve blocking the beta-receptors and therefore preventing epinephrine and norepinephrine from binding to these beta receptors. Given below is some info on the mechanism of action of beta blockers in the treatment of certain diseases.
Hypertension: Beta blockers were initially utilised for the treatment of high blood pressure. The mechanism of action of beta blockers in hypertension is not very clear, but it is believed that blood pressure is lowered due to lowering of the cardiac output. In many cases, it has been seen that an increased blood volume as well as cardiac output raises the blood pressure. Therefore, the effect of beta blockers inside the treatment of hypertension, is attributed to a reduced cardiac output. Dilation of small arteries or blood vessels due to use of these drugs might also have an effect on blood pressure. It is also believed that beta blockers affect the production of renin, thereby lowering the production of angiotensin-II, a substance identified to narrow the blood vessels and thus, raise blood pressure.
Heart Conditions: Cardioselective beta blockers have long been utilized for treating heart problems like cardiac arrhythmia, angina, increased heart rate and heart failure. The mechanism of action of beta blockers in angina, heart failure or arrhythmia is again associated with the inability of norepinephrine and epinephrine to bind themselves to the beta-1 and beta-2 receptors present in the heart and blood vessels respectively. The use of beta blockers therefore limit the physiologic responses that exercise, stress or such situations can have on the heart rate and force of contraction. Since use of beta blockers lowers the cardiac output or the amount of blood heart pumps out, the symptoms associated with these heart conditions are alleviated to a fantastic extent. Beta blockers effects like lowering of the heart rate, force of contraction and arterial pressure improves the cardiac function and thus, the possibility of 1 suffering from myocardial infarction or a heart attack is greatly reduced.
Glaucoma: These days, beta blockers are also being utilised for the treatment of an eye condition called glaucoma. Glaucoma occurs when the intraocular pressure, which could be the pressure exerted by the fluids in the eyeball, increases. This increase in eye pressure can cause damage to the optic nerve. This could give rise to blindness. To prevent a slow progression towards loss of vision, it’s essential that the intraocular pressure be restored to normal. Wondering what may be the mechanism of action of beta blockers in glaucoma? Since stimulation of beta-2 receptors within the eyes cause an increase in aqueous humor, use of beta blockers can prevent this response and assist in decreasing production of aqueous humor. This will support in stabilizing the intraocular pressure.
The mechanism of action of beta blockers is associated with the blockage of beta-receptors by beta blockers. Beta blockers compete with epinephrine and norepinephrine for the receptor sites and prevent them from binding to these sites. Thus, all of the physiological responses that result from stimulation of receptors may be prevented. Besides the aforementioned medical conditions, beta blockers are also becoming utilised for the treatment of migraine and anxiety. The accelerated heart rate which is experienced due to nervousness and fear, might be tackled with the use of these drugs. This really is why performers who wish to prevent stage fright from affecting their performance may be recommended the use of these drugs. Although these drugs can help in alleviating the symptoms of serious diseases, 1 must watch out for beta blockers side effects. These must always be taken under medical supervision.