Antihypertensives are medications that lower blood pressure in those with hypertension (high blood pressure). These medications are usually prescribed along lifestyle changes to bring blood pressure under control. Lowering the blood pressure in someone with hypertension reduces their risk of developing stroke, heart failure and other conditions.
Selecting a Blood Pressure Medication
The blood pressure medication your doctor prescribes depends on several factors, including the following:
- your blood pressure. Someone with prehypertension or mildly elevated blood pressure may benefit from a low dose of a diuretic. Someone with more severely elevated blood pressure may require treatment with multiple medications at relatively higher doses to bring his or her blood pressure under control.
- your response to previous blood pressure treatments. Medications may be added in a step-wise fashion, starting with a single medication at a low dose. If the blood pressure is not conrolled, the dosage may be increased and additional medications may be added.
- your use of other medications. Your doctor will select a medication least likely to interact with other medications you may be taking.
- your medical history and presence of other medical conditions. Your doctor may recommend a medication that treats the other condition while lowering the blood pressure. For instance, if you have angina, your doctor may recommend a beta-blocker to lower your blood pressure and also prevent your chest pain. If you have diabetes, taking a diuretic plus an ACE inhibitor can decrease your risk of heart attack and stroke. If you have diabetes, high blood pressure and kidney disease, you may also be prescribed an angiotensin II receptor blocker (ARB).
- Pregnancy. Women who are taking ACE inhibitors or ARBs for high blood pressure should not become pregnant while on this class of drugs. If you're taking an ACE inhibitor or an ARB and think you might be pregnant, see your doctor immediately.
It's not unusual to try several different blood pressure medications at different doses before finding a regimen that effectively lowers your blood pressure.
Types of Blood Pressure Medications
Blood pressure medicines work in different ways to stop or slow some of the body’s functions that cause high blood pressure. Medicines to lower blood pressure include:
- Diuretics (Water or Fluid Pills): Flush excess sodium from your body, which reduces the amount of fluid in your blood and helps to lower your blood pressure. Diuretics are often used with other high blood pressure medicines, sometimes in one combined pill.
- Beta Blockers: Help your heart beat slower and with less force. As a result, your heart pumps less blood through your blood vessels, which can help to lower your blood pressure.
- Angiotensin-Converting Enzyme (ACE) Inhibitors: Angiotensin-II is a hormone that narrows blood vessels, increasing blood pressure. ACE converts Angiotensin I to Angiotensin II. ACE inhibitors block this process, which stops the production of Angiotensin II, lowering blood pressure.
- Angiotensin II Receptor Blockers (ARBs): Block angiotensin II hormone from binding with receptors in the blood vessels. When angiotensin II is blocked, the blood vessels do not constrict or narrow, which can lower your blood pressure.
- Calcium Channel Blockers: Keep calcium from entering the muscle cells of your heart and blood vessels. This allows blood vessels to relax, which can lower your blood pressure.
- Alpha Blockers: Reduce nerve impulses that tighten blood vessels. This allows blood to flow more freely, causing blood pressure to go down.
- Alpha-Beta Blockers: Reduce nerve impulses the same way alpha blockers do. However, like beta blockers, they also slow the heartbeat. As a result, blood pressure goes down.
- Central Acting Agents: Act in the brain to decrease nerve signals that narrow blood vessels, which can lower blood pressure.
- Vasodilators: Relax the muscles in blood vessel walls, which can lower blood pressure.
To lower and control blood pressure, many people take two or more medicines. If you have side effects from your medicines, don’t stop taking your medicines. Instead, talk with your health care provider about the side effects to see if the dose can be changed or a new medicine prescribed.
Home blood pressure monitoring may be suggested to help your doctor decide if your blood pressure medication is working, and if a different dose or medication is necessary.
Combination Antihypertensive Therapy
Antihypertensives may be prescribed for use alone, or in combination with other medications. For instance, a diuretic may often be prescribed along with a beta-blocker, or ACE inhibitor.
Combining two medications of different classes allows a person to take a smaller dose of each medication, which can reduce the risk of possible side effects.
When someone’s blood pressure is very high, it is important to reduce it quickly to prevent complications. A two-drug combination generally works faster than does a single medication (monotherapy) to get blood pressure under control.
Reaching Your Blood Pressure Goal
A combination of lifestyle changes and blood pressure medication can usually bring blood pressure levels back to normal.
Sometimes high blood pressure does not respond easily to treatment, even after the use of multiple combination therapies. High blood pressure that does not respond after many attempts is referred to as "resistant hypertension". Resistant hypertension requires additional evaluation and management.
In the long run, getting your blood pressure under control leads to a longer life with fewer health problems.
Note: Consult your doctor before starting or making changes to any of your medications.
Reference: American Heart Association, National Heart Lung and Blood Institute
Last updated May 3, 2017