What are antihypertensive drugs?
Antihypertensive drugs are drugs that are designed to lower blood pressure. Typically, these drugs are used to treat high blood pressure, which is known as hypertension. The goal of these drugs is to lower blood pressure, and prevent complications associated with high blood pressure, such as coronary heart disease and stroke.
There are a variety of different types of drugs that fall under the category of antihypertensive medications, and each of these medications has their own benefits and drawbacks. Sometimes, a person will need to be on a combination of these medications in order for their blood pressure to lower. Antihypertensive drugs include:
- diuretics (eliminates sodium and water from the body to reduce blood volume, which lowers blood pressure)
- anti-adrenergics (reduces action of neurotransmitters epinephrine and norepinephrine, which relaxes blood vessels and reduces the frequency and force of the heart beats to lower blood pressure)
- direct-acting vasodilators (relaxes blood vessels)
- calcium channel blockers (reduces calcium flow into the smooth muscle of the heart and blood vessels, which weaken heart contractions and dilate blood vessels by reducing nerve impulses)
- ACE inhibitors (Blocks Angiotensin II to prevent kidneys from retaining sodium and water, which helps dilate the arteries)
- Angiotensen-receptor blockers (same as ACE inhibitors, but without as many side effects)
- Direct renin inhibitors (Blocks renin, which helps to block Angiotensin II)
Antihypertensive drugs are drugs that are taken to combat hypertension. Hypertension is abnormally high blood pressure. These drugs are taken to lower blood pressure and put someone into a safer blood pressure zone. There are many different kinds of antihypertensive drugs that are prescribed that depend on what a doctor has worked with as well as the patients stats, such as how high the blood pressure is, age, weight, and other factors.
The most straightforward answer to what antihypertensive drugs is a class of drugs that help to lower blood pressure, also known as hypertension.
Where it can become difficult is understanding that there are many different members within the class, which ultimately have the same effect (to lower blood pressure) but the mechanics of how it is done is different. Here are some of the most common classes of antihypertensive drugs:
- Thiazide Diuretics
- Calcium Channel Blockers
- ACE Inhibitors
- Beta Blockers
- Angiotensin II Receptor Antagonists (ARBs)
These are some of the more common types.
Thiazide Diuretics: The purpose of a diuretic is to help the kidneys eliminate extra salt and water in the blood and body tissue. Which will help to bring blood pressure back down, but typically the side effects outweigh the benefits of. Thiazide depletes your potassium and it can be known to increase the chances of developing diabetes.
Calcium Channel Blockers: “The calcium channel blocking agents, also called slow channel blockers or calcium antagonists, inhibit the movement of ionic calcium across the cell membrane. This reduces the force of contraction of muscles of the heart and arteries” (Enotes antihypertensive drugs article, Linked). There are different chemical classes in this group that range in the effects it has. Some may have a greater impact on the actual heart muscle and others will affect the blood vessels.
Vasodilators: These are different because they are not given long term, these are fast, effective, and very short acting. They affect the smooth muscle of arteries by relaxing them which will increase the blood vessel size which will increase the flow of blood, thereby decreasing blood pressure. Vasodilators are only used in emergency situation.
ACE Inhibitors’: The renin-angiotensin-aldosterone is a complex series of reactions that help to increase blood pressure when there is a drop in pressure. Angiotensin is a powerful vasoconstrictor (tightening the blood vessels), the opposite effect we need to lower blood pressure. The ACE Inhibitor stands for Angiotensin-converting-enzyme-inhibitor. In the response to a drop in pressure the renin-aldosterone system the last step is to convert angiotensin I to angiotensin II (increases blood pressure). The ACE inhibitor prevents that from happening conversion to happening which will help to lower the blood pressure. This medicine is typically used in conjunction with other types of medicine.
Beta Blockers: These work by reducing the adrenergic nerve stimulation, it is an excitatory nerve stimulation that will cause contractions of muscles in the arteries, veins and the heart.
Angiotensin II Receptor Antagonists: Is the same idea as ACE Inhibitors, it blocks the angiotensin which will ultimately help to lower blood pressure. However this is used when a person is intolerant of the ACE inhibitors.
This still does not cover absolutely everything but it is a lot of it and I hope this helps!!