Types of High Blood Pressure (Hypertension) Medications

High blood pressure (HBP, high BP) medications, also known as antihypertensives, are prescribed medications to treat high blood pressure. Antihypertensive medications do not cure hypertension but may lower and/or maintain the blood pressure at normal levels.

What is high blood pressure?

High blood pressure (hypertension) is a condition when blood flow exerts higher pressure on the arteries than normal. Blood pressure is measured in two values in mg Hg:

• Systolic: Blood pressure when the heart pumps out blood
• Diastolic: Blood pressure when the heart relaxes between two beats

Blood pressure (BP) is written as systolic/diastolic pressure. Blood pressure is considered to be high (elevated) if either one or both of the two values are higher than the normal range (adults’ normal range, <120/80).  Early treatment of high blood pressure can prevent damage to the arteries and heart, and the resultant life-threatening conditions such as heart attack, stroke, and kidney disease.

There are many types of high blood pressure medications and each type of medication works in a different way to bring down the blood pressure. Some patients may need to take more than one type of high BP medication. The type and dosage of medication depend on factors such as:

• How high is the BP
• The reason for the high BP
• Response to the medication
• Other co-existing conditions

The common classes of high blood pressure medications include:

• Diuretics
• Beta-blockers
• ACE (angiotensin-converting enzyme) inhibitors
• Angiotensin II receptor blockers (ARBs)
• Calcium channel blockers
• Alpha-blockers
• Alpha-2 receptor agonist
• Central agonists
• Alpha-beta blockers
• Vasodilators

Diuretics

Diuretics, also known as water pills, increase urination by reducing sodium reabsorption in the kidneys. This reduces the blood volume and lowers blood pressure. Mild hypertension may sometimes be treated with only diuretics, but they are most often prescribed in combination with other high blood pressure medications.

A primary side effect of diuretics is a loss of potassium, and patients are advised to take potassium-rich food such as bananas or orange juice with their medications. Potassium-sparing diuretics have subsequently been developed.

There are different types of diuretics, the difference being mainly in their potency and the site of their action in the kidney. Combinations of two diuretics in a single pill are also available. The three major types of diuretics prescribed for hypertension are:

Thiazide diuretics

Thiazide diuretics are usually the first-line treatment for hypertension. Following are some of the commonly prescribed thiazide diuretics:

• Chlorthalidone
• Chlorothiazide (Diuril)
• Hydrochlorothiazide or HCTZ (Microzide)
• Indapamide
• Metolazone (Zaroxolyn)

Loop diuretics

Loop diuretics are more potent than thiazides and are used primarily to treat patients with impaired kidney function or patients who are allergic to thiazides. Loop diuretics are so-called because they may prevent water reabsorption in the ascending loop of Henle in the nephron. Nephrons are functional units of kidneys, which help regulate the body’s fluid balance.

Loop diuretics include:

• Bumetanide (Bumex)
• Furosemide (Lasix)
• Ethacrynate (Edecrin)
• Torsemide

Potassium-sparing diuretics

Potassium-sparing diuretics are less potent than the other types, but reduce the reabsorption of only sodium. Potassium-sparing diuretics include:

• Amiloride hydrochloride (Midamor)
• Spironolactone (Aldactone)
• Triamterene (Dyrenium)

Combination diuretics include:

• Amiloride hydrochloride/hydrochlorothiazide
• Spironolactone/hydrochlorothiazide (Aldactazide)
• Triamterene/hydrochlorothiazide (Dyazide, Maxzide)

Beta-blockers

Norepinephrine and epinephrine (adrenaline) are hormones known as catecholamines produced by the adrenal gland. These hormones bind to proteins known as beta receptors on muscle cells, which results in more forceful contraction of heart muscles, and consequently a rise in the heart rate and blood pressure.

Beta-blockers block or reduce the effect of these hormones and as a result, the heart contracts with less force, arteries dilate, and blood pressure comes down. Beta-blockers should not be stopped suddenly as that can result in a heart attack or sudden death.

Beta-blockers include:

• Acebutolol
• Atenolol (Tenormin)
• Betaxolol hydrochloride
• Bisoprolol fumarate
• Carteolol hydrochloride
• Esmolol hydrochloride (Brevibloc)
• Metoprolol tartrate (Lopressor)
• Metoprolol succinate (Toprol-XL)
• Nadolol (Corgard)
• Nebivolol hydrochloride (Bystolic)
• Pindolol
• Propranolol hydrochloride (Inderal)
• Sotalol hydrochloride (Betapace)
• Timolol maleate

Combination of beta-blocker and diuretic:

• Bisoprolol/hydrochlorothiazide (Ziac)

ACE inhibitors

The kidneys secrete an enzyme known as renin when they detect low blood pressure. Renin activates angiotensin I, a hormone produced in the liver, which is converted into angiotensin II by the angiotensin-converting enzyme (ACE). Angiotensin II is a powerful chemical that makes the smooth muscles around the blood vessels contract, increasing blood pressure.

ACE inhibitors prevent the formation of angiotensin II by inhibiting ACE, which keeps blood vessels relaxed and the blood pressure low. Following are commonly prescribed ACE inhibitors:

• Benazepril hydrochloride (Lotensin)
• Captopril (Capoten)
• Enalapril Maleate (Vasotec)
• Fosinopril sodium
• Lisinopril (Prinivil, Zestril)
• Moexipril hydrochloride
• Perindopril erbumine
• Quinapril hydrochloride (Accupril)
• Ramipril (Altace)
• Aliskiren hemifumarate (Tekturna) -- renin inhibitor

Combination of ACE inhibitors and calcium channel blockers include:

• Perindopril arginine/amlodipine besylate (Prestalia)
• Trandolapril/verapamil hydrochloride (Tarka)

Angiotensin II receptor blockers (ARBs)

Angiotensin II hormone must bind with receptor sites on blood vessels to make them contract. ARBs help lower blood pressure by preventing angiotensin from binding to the receptor sites.

Examples of ARBs include:

• Azilsartan medoxomil (Edarbi)
• Candesartan (Atacand)
• Irbesartan (Avapro)
• Losartan potassium (Cozaar)
• Olmesartan medoxomil (Benicar)
• Telmisartan (Micardis)
• Valsartan (Diovan)

Calcium channel blockers (CCBs)

The smooth muscles of the heart and blood vessels require calcium to contract. Calcium channel blockers reduce the calcium flow into the muscle cells, making the heart pump with less force and blood vessels relax, resulting in lower blood pressure.

Calcium channel blockers are of three classes:

• Dihydropyridines: Primary effect on the blood vessels
• Benzothiazines: Primary effect on the heart muscles
• Phenylalkylamines: Effect on both heart and blood vessels

Following is a list of calcium channel blockers:

• Dihydropyridines
  • Amlodipine besylate (Norvasc)
  • Amlodipine combination drugs:
    • Amlodipine and atorvastatin (Caduet)
    • Amlodipine and benazepril (Lotrel)
    • Amlodipine and valsartan (Exforge)
    • Amlodipine and telmisartan (Twynsta)
    • Amlodipine and olmesartan (Azor)
    • Amlodipine, olmesartan and hydrochlorothiazide (Tribenzor)
    • Amlodipine and perindopril (Prestalia)
  • Clevidipine (Cleviprex)
  • Felodipine
  • Isradipine
  • Nicardipine hydrochloride (Cardene)
  • Nifedipine (Procardia, Adalat CC)
  • Nimodipine
  • Nisoldipine (Sular)
• Benzothiazine
  • Diltiazem hydrochloride (Cardizem, Tiazac)
• Phenylalkylamine
  • Verapamil hydrochloride (Calan SR, Verelan)

Alpha-blockers

Catecholamines epinephrine and norepinephrine also stimulate alpha-1 receptors in the smooth muscles of blood vessels making them contract. Alpha-blockers block their effect, which results in dilation of blood vessels and lower blood pressure. Alpha-blockers are not usually first-line treatment. Alpha-blockers include:

• Doxazosin mesylate (Cardura)
• Prazosin hydrochloride (Minipress)
• Terazosin hydrochloride

Alpha-beta blockers

Alpha-beta blockers affect both alpha and beta receptors, resulting in slowing of the heart’s pumping as well as preventing blood vessel contraction. Alpha-beta blockers include:

• Carvedilol (Coreg)
• Labetalol (Trandate)

Alpha-2 receptor agonist

Alpha-2 receptors inhibit the transmission of nerve signals by neurotransmitters that stimulate the release of norepinephrine. Alpha-2 receptor agonists boost the activity of alpha-2 receptors. The alpha-2 receptor agonist, which is particularly used to treat hypertension during pregnancy is:

• Methyldopa

Central agonists

Central agonists work on the central nervous system to decrease the constriction of blood vessels and help lower blood pressure. Central agonists include:

• Clonidine hydrochloride (Catapres)
• Guanfacine hydrochloride

Vasodilators

Vasodilators relax the arterial muscles which allow the blood vessels to dilate, decreasing the blood pressure. Vasodilators include:

• Hydralazine hydrochloride
• Minoxidil

According to recent statistics, the most popular high blood pressure medications in terms of dollar sales include:

• Angiotensin II receptor blocker valsartan (Diovan)
• Beta-blocker metoprolol
• Generic combination of valsartan and diuretic HCTZ
• Angiotensin II receptor blocker Olmesartan (Benicar)
• Combination of olmesartan and HCTZ (Benicar HCT)

In terms of prescriptions, the most common high blood pressure medications include:

• ACE inhibitor lisinopril (Prinivil, Zestril)
• Calcium channel blocker amlodipine besylate (Norvasc)
• Diuretic hydrochlorothiazide (HCTZ)

The choice of high blood pressure medication depends on several factors such as a patient’s general health, age, ethnicity, drug sensitivity, and co-existing conditions if any. For instance:

• Beta-blockers may not be suitable for a hypertensive patient with asthma because they can aggravate respiratory conditions.
• Calcium channel blockers and diuretics may not suit patients prone to constipation.
• A combination of two types of low dose medications instead of a high dose of a single medication may be preferable for an elderly patient.
• African-Americans respond better to some medications than others, and diuretics or calcium channel blockers are recommended as first-line treatment, with a possible additional class of drug.

• Please visit our medication section of each drug within its class for more detailed information.
• If your prescription medication isn’t on this list, remember to look in our medication section or discuss it with your healthcare provider and pharmacist.
• It is important to discuss all the drugs you take with your doctor and understand their effects and possible side effects.
• Never stop taking your medication and never change your dose or frequency without consulting with your doctor.