Alpha-Blockers: Its uses, Function, and Side Effects.
These are the medicines that are prescribed to treat high blood pressure(hypertension) and treat enlarged prostate. Alpha-blockers lowers high blood pressure by blocking the transmission of a hormone called Norepinephrine. This hormone when released tightens the walls in some arteries and veins. So, preventing from releasing this hormone will, as a result, improve the blood flow and lower blood pressure.
Alpha-Blockers were used in the treatment of heart failure, but now they are rarely used to treat the heart as there are now better medicines available. Aside from high blood pressure and enlarged prostate, alpha-blockers are used to treat ureteric stones.
How does Alpha-Blocker work?
Alpha-Blockers affect the sympathetic nervous system by restraining alpha receptors released in the body. There are two types of alpha receptors.
1. Alpha receptor 1: These are on the vascular muscle of the skin, kidney, opening of the gastrointestinal system, and brain. If these receptors are released in the body, they can constrict the vessels. These vessels are tightened by the hormones such as Epinephrine and Norepinephrine. This tightening decreases the blood flow, thus increasing blood pressure.
2. Alpha receptor 2: These receptors are located on the peripheral nerve endings. These receptors can release norepinephrine which constricts and dilates the blood vessels (veins and arteries).
To inhibit these alpha receptors alpha-blockers are used. There are three types of alpha-blockers.
• Nonselective Alpha-Blockers: These are used to prevent the alpha receptor 1 and alpha receptor 2. These constrict the hormones like norepinephrine which as result does not tighten the muscles of the walls in arteries and veins. These are used to treat a benign noncancerous tumor in the adrenal gland called pheochromocytoma.
• Selective Alpha-1 blockers: These blockers prevent norepinephrine from activating the alpha 1 receptors that constrict the blood vessels and improve the flow of the blood. They also improve the urine flow in patients suffering from enlarged prostate or patients suffering from benign prostatic hyperplasia.
• Selective Alpha-2 Blockers: As suggested by the name these inhibit the release of alpha 2 receptors and stop the tightening of the blood vessels by preventing norepinephrine to stimulate these receptors.
What are the uses of Alpha-Blockers?
Alpha-Blockers are generally used to treat high blood pressure and enlarged prostate; however, they are prescribed for many other diseases. They are used to treat the following:
• High Blood Pressure: High blood pressure or hypertension is caused when the blood against your artery walls is very high that which may lead to heart disease. High blood pressure happens when the amount of blood flow from the heart is more and the blood flowing to the body is restricted because your arteries are narrower. There are two types of blood pressure:
▪ Systolic pressure (Top number): It measures the pressure in the arteries when the heart beats.
▪ Diastolic pressure (bottom number): It measures the pressure in the arteries between the heartbeats.
People with high blood pressure may experience symptoms like headaches, shortness of breath, or nosebleeds. These may only appear if your blood pressure reaches a very
• Benign Prostate Hyperplasia: This condition generally affects older men. It is also called prostate gland enlargement. In this, an enlarged prostate can block the flow of urine or make it difficult to urinate. These may lead to larger health issues like urinary tract, bladder tract, and kidney problems. The symptoms of the enlarged prostate are:
▪ Urgent need to urinate
▪ Increase in the frequency of urination
▪ Difficulty in urination
▪ Unable to empty the bladder.
▪ Weak urine stream
▪ Urinary tract infection
▪ Blood in the urine
• Pheochromocytoma: This is a benign noncancerous tumor that grows on the adrenal gland. They mostly occur in people between the age of 20 and 50. The tumor releases the hormones which cause high blood pressure, headache, and panic attack. The symptoms of pheochromocytoma are:
▪ High blood pressure
▪ Headache
▪ Rapid heartbeat
▪ Sweating more than usual
▪ Shortness of breath
▪ Panic attack
▪ Tremors
▪ Anxiety
▪ Weight loss
▪ Constipation
They can be cured by certain medications like alpha-blockers and or be removed by surgery.
• Heart failure: Heart failure happens due to its inability to pump out the oxygenated blood. This does not provide blood to the other organs of the body like the brain, liver, and kidney. They may occur because of the failure of both ventricles that are left and right. The signs and symptoms of a stroke are:
▪ Shortness of breath
▪ Asthma
▪ Edema or swelling
▪ Pooling of blood in the body
▪ Pooling of the blood in the liver
▪ Hypertrophy: enlargement of the heart
▪ Cyanosis: blueness or duskiness
There are many causes of heart failure. Like, as heart muscles may weaken from viral infections, exposure to alcohol for a long time, a blocked valve causing blood leakage, coronary artery disease, or high blood pressure.
• Dermal Necrosis: It is a condition in which there is blood clotting. Blood clotting blocks the blood vessels which in turn damages the affected area of the skin. Skin necrosis affects the areas of the skin with high-fat content. It usually affects women more than men between the age of 50 and 70 years.
It is caused when warfarin (a blood thinner) is given to people. It usually happens when the dose of warfarin increases, the dose is not taken regularly, and if you have liver disease.
• Raynaud’s phenomenon: In this condition, the blood flow to the fingers is decreased. There are cases where the blood flows less to the ears, toes, nipples, knees, or nose. This happens due to the blood spasms caused by cold, stress, or when you are upset. These may happen on their own known as primary form or may occur with other diseases called secondary form. The other diseases which may occur with this are:
▪ Lupus
▪ Scleroderma
▪ CREST syndrome
▪ Buerger disease
▪ Sjogren syndrome
▪ Rheumatoid arthritis
▪ Occlusive vascular disease, such as atherosclerosis
▪ Polymyositis
▪ Blood disorders, such as Cryoglobulinemia
▪ Thyroid disorders
▪ Pulmonary hypertension
It is most common between the ages of 15 and 25. It may be caused due to some blood disorders. These blood disorders may lead increase the blood thickness.
• These are also used to improve the blood flow in the body by stabilizing pulmonary flow. This widens the blood vessels (arteries and veins) ensuring good systemic blood flow throughout the body.
List of Alpha-Blockers
There block the alpha receptors in the body. They are widely available and are used mainly to treat high blood pressure. Some of the common Alpha-Blockers are:
1) Cardura, Cardura XL
2) Minipress(prazosin)
3) Terazosin
4) Flomax
5) Uroxatral
6) Rapaflo
7) Dibenzyline
These come in tablet form or capsules and have to be taken according to the prescription of your doctor.
When should we use the Alpha-Blockers?
They should be taken only on your doctor’s recommendation. They are usually taken to treat high blood pressure and enlarged prostate.
In case of high blood pressure:
They are not usually the first course of treatment a doctor may recommend and are prescribed by doctors who specialize in treating hypertension. And they usually prescribe them if other medicines do not work. They should be used if:
• The other medicines prescribed by the doctors like beta-blockers, ACE inhibitors, or diuretics are not working. You can then take alpha-blockers along with these other medicines.
• For some reason you cannot take beta-blockers, ACE inhibitors, or diuretics.
In the case of benign prostate hyperplasia:
In the case of an enlarged prostate, the alpha-blockers should only be taken when you are experiencing higher discomfort from your symptoms. If your urgency to urinate increases over time, the problem in urinating increases then you can go to your doctor and they will prescribe the right medications.
Your treatment plan is totally on the doctor and how bothered you are by your benign prostate hyperplasia.
How long should you take Alpha-Blockers?
The diseases for which these alpha-blockers are taken are usually long-term. So, they need to be taken for life. However, if these conditions come under control, then you can stop taking them.
Hypertension
Sometimes high blood pressure comes under control after taking the medication for 2 to 3 years. If that happens then you can stop taking medications. If you want to stop taking the medications then you should consider making some changes in your lifestyle, such as, eating healthy and exercising regularly. But first, you should take advice from your doctor.
Enlarged prostate
For enlarged prostate, you need to take medications for life. But depending on how the treatment works for you can stop the medications. Your doctor will review your symptoms every 4-6 weeks after you start the treatment. And after your symptoms are settled, you can go to your doctor for a follow-up every year.
What are the side-effects of taking Alpha-Blockers?
There are rarely any side effects from Alpha-blockers. But usually, low-blood pressure and dizziness can happen and there is a risk of you falling and breaking your bone. Therefore, when starting these medications doctors tell you to take them at night during bedtime. Other side-effects include:
• Headache
• Tachycardia
• Stuffiness in the nose
• Swelling in the legs and feet
• Problems in performing a sexual activity, like decreased ejaculation.
Alpha-blockers usually are not the first choice of medications to treat high blood pressure and enlarged prostate by doctors. They are prescribed if the other medications are not working properly. These are not taken alone; they are usually taken along with the other medications.
These medications are easily available in the market, but you can only get them through your doctor’s prescription. So, if you suffer from any of the above-mentioned diseases you should visit your doctor and then get the Alpha-Blockers.
