Alpha vs Beta Blockers – Difference and Comparison

What is an Alpha-Blocker?

Alpha is a type of drug which lowers blood pressure by preventing the norepinephrine hormone from tightening the smooth muscle on the wall of veins and arteries. They act on a-adrenergic receptors and are a class of drugs.  The receptors have a common function which is vasoconstriction. Alpha-blockers prevent such function upon building any receptor. As which result alpha blocker helps in binding the receptors in which the blood vessel remains relaxed and open, and it reduces the blood pressure and improves blood flow. Alpha-blocker works on blood pressure alone.

They are of two types long-acting and short-acting. Long-acting drugs take a longer time to effect while short-acting show their effect very quickly but last for a few hours. Therefore the types of alpha-blocker depend upon the patient’s health condition.

Example of alpha-blocker which helps to treat high blood pressure-

1. Prazosin
2. Doxazosin
3. Terazosin

However, alpha-blockers are not the first choice for treating blood pressure. It includes side effects such as headache, dizziness, weakness, pounding heartbeat, etc.  Usually, other medications like diuretics are used when it is difficult to control blood pressure. Alpha-blockers can treat other diseases like erectile dysfunction, benign prostatic hyperplasia, and Raynaud’s disease.

What are Beta-Blockers?

Beta-blockers are a type of drug that lowers blood pressure which blocks the effects of the hormone epinephrine and it reduces the heartbeat rate. Beta-blockers are antagonists of receptors for catecholamine such as epinephrine. Such receptors are adrenergic beta, receptors of the sympathetic nervous system which meditate the flight-or-flight responses. Some beta blocker blocks the activation of entire types of b- adrenergic receptors. 

Some are selective for one of all three known beta receptors: B1, B2, and B3 receptors. The B1 –adrenergic receptors are mostly in the kidney and heart. B2- adrenergic receptors can be found in the liver, lungs, uterus, vascular smooth muscle, gastrointestinal tract, and skeletal muscle. And B3 – adrenergic receptor is existing in fat cells.

Beta-blockers are predominantly used to treat abnormal heart tempos and protect patients from a second heart attack from the second attack. Some examples are atenolol, acebutolol, metoprolol, nadolol, propranolol, and bisoprolol. They also have common side effects such as cold feet or hands, fatigue, depression, shortness of breath, troubles sleeping and weight gain, etc.

Difference Between Alpha and Beta Blockers

1. Alpha-beta doesn’t cause any weight gain although beta-blocker can cause weight gain.
2. Alpha-blockers work for blood pressure single-handedly however beta-blockers work for both blood pressure and heart.
3. Alpha-blocker medicine works on the hormone of noradrenaline or norepinephrine however beta-blockers work on adrenaline or epinephrine.
4. Alpha works on the blood to open up the blood vessels while the beta blockers work on the heart to flow blood.
5. Alpha-blockers are used to treat BPH, hypertension, Raynaud’s disease, or erectile dysfunction however beta-blockers are used to treat stroke, hypertension, or another cardiovascular disease.
6. Alpha-blocker controls only blood pressure whereas beta-blockers control the heart rate as well as blood pressure
7. Alpha-blockers have side effects such as headache, dizziness, pounding heartbeat while beta-blocker has the side effect of fatigue, weight gain, depression, cold feet or hands, shortness of breath, etc.

Comparison Between Alpha and Beta Blockers

References

1. https://www.tandfonline.com/doi/abs/10.3109/10641969909061011
2. https://www.bmj.com/content/288/6418/671.abstract