Medications that Lower Blood Pressure

If lifestyle changes do not lower blood pressure enough, your doctor may prescribe blood pressure-lowering medication. There are five main classes of medication that can do this. Your doctor will choose an appropriate medication for you based on your age and any other medical conditions you may have. It is common for people to require two or more different medications to get their blood pressure levels as low as they should be.

ACE inhibitors

ACE (angiotensin-converting enzyme) inhibitors block a series of events in the bloodstream that would otherwise cause the muscular walls of small arteries to contract, which would increase blood pressure. They are particularly useful in people with diabetes, heart failure, kidney disease or a previous heart attack or stroke. Side effects may include cough, an increased blood potassium level, rash and angioedema (an allergic swelling that affects the face, lips and windpipe). ACE inhibitors available in Canada include benazepril (Lotensin^®), captopril (Capoten^®), cilazapril (Inhibace^®), enalapril (Vasotec^®), fosinopril (Monopril^®), lisinopril (Prinivil^®, Zestril^®), perindopril (Coversyl^®), quinapril (Accupril^®), ramipril (Altace^®) and trandolapril (Mavik^®).

Angiotensin receptor blockers (ARBs)

ARBs block the action of an enzyme called angiotensin II, which normally causes blood vessels to become narrower. Blocking this enzyme stops small arteries from constricting and thus raises the blood pressure. They are particularly useful in people with diabetes. Side effects may include dizziness, an increased blood potassium level and, rarely, angioedema. ARBs available in Canada include candesartan (Atacand^®), eprosartan (Teveten^®), irbesartan (Avapro^®), losartan (Cozaar^®), telmisartan (Micardis^®) and valsartan (Diovan^®).

Beta-blockers

Beta-blockers block the effects of part of the nervous system – the part responsible for raising blood pressure in response to stress. They are especially useful in people with angina or a previous heart attack. Side effects may include spasm of the airways, an abnormally slow heart rate, possible masking of low blood sugar levels after insulin injections, impaired peripheral circulation, insomnia, fatigue, shortness of breath and sexual dysfunction. Available beta-blockers used to treat high blood pressure include acebutolol (Rhotral^®, Sectral^®), atenolol (Tenormin^®), bisoprolol (Monocor^®), labetalol (Trandate^®), metoprolol (Betaloc^®, Lopresor^®, Lopresor SR^®), nadolol (generic), oxprenolol (Trasicor^®), pindolol (Visken^®) and timolol (generic).

Calcium channel blockers

Calcium channel blockers (also called calcium antagonists) cause blood vessels to expand. There are different types of calcium channel blockers, with properties that are useful in different kinds of patients. More common side effects may include dizziness, swelling of the ankles, flushing, palpitations, and headache. Calcium channel blockers available in Canada include amlodipine (Norvasc^®), diltiazem (Cardizem^®, Cardizem CD^®, Tiazac^®, Tiazac XC^®), felodipine (Plendil^®, Renedil^®), nifedipine (Adalat XL^®), nimodipine (Nimotop^®) and verapamil (Covera-HS^®, Isoptin SR^®).

Diuretics

Diuretics are sometimes called “water pills”. They work by helping the kidney eliminate salt and water, which lowers the amount of fluid in the body. Less fluid means a smaller volume of blood, and therefore less pressure of the blood against the walls of the blood vessels. Diuretics also cause blood vessels to widen, which also reduces pressure.

Side effects of diuretics include decreased blood levels of potassium and magnesium, increased blood levels of calcium and uric acid, sexual dysfunction in men, and digestive upset. Diuretics available in Canada include amiloride (Midamor^®), bumetanide (Burinex^®), chlorthalidone (generic), ethacrynic acid (Edecrin^®), furosemide (Lasix^®), hydrochlorothiazide (generic), spironolactone (Aldactone^®) and triamterene (generic). They are particularly useful for people with heart failure, chronic kidney failure, or previous stroke.

Combination therapies

Instead of taking two separate blood pressure-lowering medications, sometimes a “fixed dose combination therapy” is available that combines both medications in a single pill. Ask your healthcare professional for more information on such alternatives.

One available "fixed dose combination therapy" (Caduet^®) combines the calcium channel blocker amlodipine with a statin (a medication to treat high cholesterol ). This can ease the process of taking the medication, since it requires taking only one pill instead of two.

The most common type of combination medication for the treatment of hypertension pairs a diuretic with another type of medication. For example, the diuretic hydrochlorothiazide is available in combination with various ACE inhibitors: cilazapril (Inhibace Plus^®), enalapril (Vaseretic^®), lisinopril (Prinzide^®, Zestoretic^®), quinapril (Accuretic^®) or ramipril (Altace HCT^®). It is also available in combination with any of the available ARBs: candesartan (Atacand Plus^®), eprosartan (Teveten Plus^®), irbesartan (Avalide^®), losartan (Hyzaar^®), telmisartan (Micardis Plus^®) and valsartan (Diovan-HCT^®).

Hydrochlorothiazide is also available in combination with the beta-blocker pindolol (Viskazide^®), and another diuretic, chlorthalidone, is available in combination with the beta-blocker atenolol (Tenoretic^®).

Three combination medications include two types of diuretic: Aldactazide^® (hydrochlorothiazide and spironolactone), Moduret^® (hydrochlorothiazide and amiloride) and the generic combination of hydrochlorothiazide and triamterene.

Finally, there are combination medications that include the ACE inhibitor ramapril and the calcium channel blocker felodipine (Altace Plus Felodipine^®), or the ACE inhibitor trandolapril and the calcium channel blocker verapamil (Tarka^®).