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Drug Treatment of High Blood Pressure


George L. Bakris

, MD, University of Chicago School of Medicine

Last full review/revision Mar 2021| Content last modified Mar 2021

High blood pressure is very common. It often does not cause symptoms; however, high blood pressure can increase the risk of stroke, heart attacks, and heart failure. Therefore, it is important to treat high blood pressure. People with high blood pressure should make changes in their lifestyle to help reduce blood pressure. However, if such changes do not sufficiently reduce blood pressure, drug treatment is needed.

Drugs that are used in the treatment of high blood pressure are called antihypertensives. With the wide variety of antihypertensives available, high blood pressure can be controlled in almost anyone, but treatment has to be tailored to the individual. (See also High Blood Pressure.) Treatment is most effective when the person and doctor communicate well and collaborate on the treatment program.

Different types of antihypertensives reduce blood pressure by different mechanisms, so many different treatment strategies are possible. For some people, doctors use a stepped approach to drug therapy: They start with one type of antihypertensive and add others as necessary. For other people, doctors find a sequential approach is preferable: They prescribe one antihypertensive, and if it is ineffective, they stop it and prescribe another type. For people with blood pressure at or above 140/90 mm Hg, usually two drugs are started at the same time. In choosing an antihypertensive, doctors consider such factors as

  • The person's age, sex, and race
  • The severity of high blood pressure
  • The presence of other conditions, such as diabetes or high blood cholesterol levels
  • Potential side effects, which vary from drug to drug
  • The costs of the drugs and of tests needed to check for certain side effects

A majority of people (more than 74%) ultimately require two or more drugs to reach their blood pressure goal.

Most people tolerate their prescribed antihypertensive drugs without problems. But any antihypertensive drug can cause side effects. So if side effects develop, a person should tell the doctor, who can adjust the dose or substitute another drug. Usually, an antihypertensive drug must be taken indefinitely to control blood pressure.

Adrenergic blockers

Adrenergic blockers include alpha-blockers, beta-blockers, alpha-beta blockers, and peripherally acting adrenergic blockers. These drugs block the effects of the sympathetic division, the part of the autonomic nervous system that can rapidly respond to stress by increasing blood pressure.

Beta-blockers are the most commonly used adrenergic blockers. They are particularly useful for whites, young people, and people who have had a heart attack. They are also useful for people who have a rapid heart rate, angina pectoris (chest pain due to inadequate blood supply to the heart muscle), or migraine headaches. The risk of side effects is higher for older people.

Alpha-blockers are no longer used as the main therapy because they do not decrease the risk of death. Peripherally acting adrenergic blockers are usually only used if a third or fourth type of drug is needed to control blood pressure.

Angiotensin-converting enzyme inhibitors

Angiotensin-converting enzyme (ACE) inhibitors lower blood pressure in part by dilating arterioles. They dilate arterioles by preventing the formation of angiotensin II, a chemical produced in the body that causes arterioles to constrict. Specifically, these inhibitors block the action of angiotensin-converting enzyme, which converts angiotensin I to angiotensin II (see figure Regulating Blood Pressure). These drugs are particularly useful for people with coronary artery disease or heart failure, whites, young people, people with protein in their urine because of chronic kidney disease or diabetic kidney disease, and men who develop sexual dysfunction as a side effect of another antihypertensive drug.

Angiotensin II receptor blockers

Angiotensin II receptor blockers (ARBs) lower blood pressure by a mechanism similar to the one used by angiotensin-converting enzyme inhibitors: They directly block the action of angiotensin II, which causes arterioles to constrict. Because the mechanism is more direct, angiotensin II receptor blockers may cause fewer side effects.

Calcium channel blockers

Calcium channel blockers cause arterioles to dilate by a completely different mechanism. They are particularly useful for blacks and older people. Calcium channel blockers are also useful for people who have angina pectoris, certain types of rapid heart rate, or migraine headaches. Calcium channel blockers may be short-acting or long-acting. Short-acting calcium channel blockers are not used to treat high blood pressure. Reports suggest that people using short-acting calcium channel blockers may have an increased risk of death due to heart attack, but no reports suggest such effects for long-acting calcium channel blockers.

Centrally acting alpha agonists

Centrally acting alpha-agonists lower blood pressure through a mechanism that somewhat resembles that of adrenergic blockers. By stimulating certain receptors in the brain stem, these agonists inhibit the effects of the sympathetic division of the nervous system. These drugs are rarely used now.

Direct vasodilators

Direct vasodilators dilate blood vessels by another mechanism. A drug of this type is almost never used alone; rather, it is added as a second drug when another drug alone does not lower blood pressure sufficiently.

Antihypertensive Drugs



Some Side Effects

Adrenergic blockers


Fainting (syncope) with the first dose, awareness of rapid heartbeats (palpitations), dizziness, low blood pressure when the person stands (orthostatic hypotension), and fluid retention (edema)


Spasm of the airways (bronchospasm), an abnormally slow heart rate (bradycardia), heart failure, possible masking of low blood sugar levels after insulin injections, impaired peripheral circulation, insomnia, fatigue, shortness of breath, depression, Raynaud syndrome, vivid dreams, hallucinations, and sexual dysfunction

With some beta-blockers, an increased triglyceride level

Alpha-beta blockers

  • Carvedilol
  • Labetalol

Low blood pressure when the person stands and spasm of the airways

Angiotensin-converting enzyme (ACE) inhibitors

  • Benazepril
  • Captopril
  • Enalapril
  • Fosinopril
  • Lisinopril
  • Perindopril
  • Quinapril
  • Ramipril
  • Trandolapril

Cough (in up to 20% of people), low blood pressure, an increased potassium level, rash, angioedema (allergic swelling that affects the face, lips, and windpipe and may interfere with breathing), and, in pregnant women, serious injury to the fetus

Angiotensin II receptor blockers (ARBs)

  • Azilsartan
  • Candesartan
  • Eprosartan
  • Irbesartan
  • Losartan
  • Olmesartan
  • Telmisartan
  • Valsartan

Dizziness, an increased potassium level, angioedema (rarer than with ACE inhibitors), and, in pregnant women, serious injury to the fetus

Calcium channel blockers


  • Amlodipine
  • Felodipine
  • Isradipine
  • Nicardipine
  • Nifedipine (sustained-release only)
  • Nisoldipine

Dizziness, fluid retention in the ankles, flushing, headache, heartburn, enlarged gums, and an abnormally fast heart rate (tachycardia)


  • Diltiazem (sustained-release only)
  • Verapamil

Headache, dizziness, flushing, fluid retention, problems in the heart's electrical conduction system (including heart block), an abnormally slow heart rate (bradycardia), heart failure, and enlarged gums

With verapamil, constipation

Centrally acting alpha-agonists

  • Clonidine
  • Guanabenz
  • Guanfacine
  • Methyldopa

Drowsiness, dry mouth, fatigue, an abnormally slow heart rate, rebound high blood pressure when the drug is withdrawn (except with methyldopa), and sexual dysfunction

With methyldopa, depression, low blood pressure when the person stands, and liver and autoimmune disorders

Direct vasodilators

  • Hydralazine
  • Minoxidil

Headache, an abnormally fast heart rate (tachycardia), and fluid retention


Loop diuretics

  • Bumetanide
  • Furosemide
  • Ethacrynic acid
  • Torsemide

Decreased levels of potassium and magnesium, temporarily increased levels of blood sugar and cholesterol, an increased level of uric acid, sexual dysfunction in men, and digestive upset

Potassium-sparing diuretics

With all, a high potassium level and digestive upset

With spironolactone, breast enlargement in men (gynecomastia) and menstrual irregularities in women

Thiazide and thiazide-type diuretics

  • Bendroflumethiazide
  • Chlorothiazide
  • Chlorthalidone
  • Hydrochlorothiazide
  • Hydroflumethiazide
  • Indapamide
  • Methyclothiazide

Decreased levels of potassium and magnesium, increased levels of calcium and uric acid, sexual dysfunction in men, and digestive upset


A thiazide or thiazide-type diuretic (such as chlorthalidone or indapamide) may be the first drug given to treat high blood pressure. Diuretics can cause blood vessels to widen (dilate). Diuretics also help the kidneys eliminate sodium and water, decreasing fluid volume throughout the body and thus lowering blood pressure.

Thiazide diuretics cause potassium to be excreted in the urine, so potassium supplements or a diuretic that does not cause potassium loss or that causes potassium levels to increase (a potassium-sparing diuretic) sometimes must be taken with a thiazide diuretic. Usually, potassium-sparing diuretics are not used alone because they do not control blood pressure as well as thiazide diuretics do. However, the potassium-sparing diuretic spironolactone is sometimes used alone.

Diuretics are particularly useful for blacks, older people, obese people, and people with heart failure or chronic kidney disease.

More Information

The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.

  • American Heart Association: High blood pressure: Comprehensive resource to help people understand causes of high blood pressure and manage the lifestyle changes required for treatment

Drugs Mentioned In This Article

Generic Name Select Brand Names
Hydrochlorothiazide MICROZIDE
Methyclothiazide No US brand name
Ethacrynic acid EDECRIN
Chlorothiazide DIURIL
Chlorthalidone THALITONE
Spironolactone ALDACTONE
Trandolapril MAVIK
Propranolol INDERAL
Telmisartan MICARDIS
Triamterene DYRENIUM
Candesartan ATACAND
Nisoldipine SULAR
Nicardipine CARDENE
Eplerenone INSPRA
Eprosartan TEVETEN
Olmesartan BENICAR
Methyldopa No brand name
Benazepril LOTENSIN
Guanfacine TENEX
Felodipine PLENDIL
Bisoprolol ZEBETA
Acebutolol SECTRAL
Irbesartan AVAPRO
Amlodipine NORVASC
Azilsartan EDARBI
Furosemide LASIX
Carvedilol COREG
Clonidine CATAPRES
Torsemide DEMADEX
Nebivolol BYSTOLIC
Betaxolol BETOPTIC
Minoxidil ROGAINE
Enalapril VASOTEC
Verapamil CALAN
Doxazosin CARDURA
Quinapril ACCUPRIL
Captopril CAPOTEN
Amiloride MIDAMOR
Terazosin HYTRIN
Valsartan DIOVAN
Losartan COZAAR
Ramipril ALTACE

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