Blood pressure medications also known as antihypertensive drugs or hypotensives are drugs that are employed to relax, dilate and lower blood pressure (BP) to normal. It must be pointed out that there is no hard line drawn between hypertensive and normotensive subjects. However, it is generally accepted that systolic/diastolic blood pressure of 120/80 mm Hg or less is normal while a figure of systolic/diastolic blood pressure of 140/90 mmHg is considered the upper limit of ‘normal’.
Read Also: Understanding blood pressure readings
Several antihypertensive drugs with different sites and mechanism of actions are now available. Nevertheless, none can be said to be the ideal antihypertensive medication. Initial drug selection depends on the degree of blood pressure elevation and presence of compelling indications for selected drugs.
Contents
Classes of blood pressure medications
The classes of blood pressure medications include
- Angiotensin-Converting Enzyme Inhibitors (ACEIs)
- Beta-blockers
- Diuretics
- Angiotensin II receptor blockers (ARBs)
- Calcium channel blockers (CCBs)
- α-Adrenoreceptor blockers
- Central α2-agonists
- Direct vasodilators
- Direct renin inhibitors
- Aldosterone receptor antagonists (ARAs)
1. Angiotensin-Converting Enzyme Inhibitors (ACEIs)
The ACEIs directly inhibit conversion of angiotensin I to angiotensin II, a potent vasoconstrictor and stimulator of aldosterone secretion. This helps blood vessels relax and reduces blood pressure. ACEIs also block kininase production and thus, prevent degradation of bradykinin. This appears to be important in the aetiology of ACEI induced cough, which is a troublesome side effect in 10–20% of users.
Examples of ACE inhibitors used in the management of hypertension include
| Generic name | Common brand names | Usual dose range (mg/day) | Daily frequency |
| Benazepril | Lotensin | 10 – 40 | 1 or 2 |
| Captopril | Capoten | 12.5 – 150 | 2 or 3 |
| Enalapril | Vasotec | 5 – 40 | 1 or 2 |
| Fosinopril | Monopril | 10 – 40 | 1 |
| Lisinopril | Prinivil, Zestril | 10 – 40 | 1 |
| Moexipril | Univasc | 7.5 – 30 | 1 or 2 |
| Perindopril | Aceon | 4 – 16 | 1 |
| Quinapril | Accupril | 10 – 80 | 1 or 2 |
| Ramipril | Altace | 2.5 – 10 | 1 or 2 |
| Trandolapril | Mavik | 1 – 4 | 1 |
Some noted possible side effects of ACEIs
- Dry cough
- Rash
- Taste disturbance
- Renal dysfunction
- Angioedema
2. Beta-blockers (Beta-Adrenergic Blockers)
β-Blockers have several direct effects on the cardiovascular system. They can decrease cardiac contractility and cardiac output (CO), lower heart rate, blunt sympathetic reflex with exercise, reduce central release of adrenergic substances, inhibit norepinephrine release peripherally, and decrease renin release from the kidney. All these contribute to their antihypertensive effects.
Examples of beta-blockers include
| Generic name | Common brand names | Usual dose range (mg/day) | Daily frequency |
| a. Cardioselective beta-blockers | |||
| Atenolol | Tenormin | 25 – 100 | 1 |
| Betaxolol | Kerlone | 5 – 20 | 1 |
| Bisoprolol | Zebeta | 2.5 – 10 | 1 |
| Metoprolol tartrate | Lopressor | 100 – 400 | 2 |
| Metoprolol succinate extended release | Toprol XL | 50 – 200
| 1 |
| b. Nonselective beta-blockers | |||
| Nadolol | Corgard | 40 – 120 | 1 |
| Propranolol | Inderal | 160 – 480 | 2 |
| Propranolol long acting | Inderal LA, Inderal XL, InnoPran XL | 80 – 320 | 1 |
| Timolol | Blocadren | 10 – 40 | 1 |
| c. Beta-blockers with intrinsic sympathomimetic activity | |||
| Acebutolol | Sectral | 200 – 800 | 2 |
| Carteolol | Cartrol | 2.5 – 10 | 1 |
| Pindolol | Visken | 10 – 60 | 2 |
| d. Mixed α- and β- blockers | |||
| Carvedilol | Coreg | 12.5 – 50 | 2 |
| Carvedilol phosphate | Coreg CR | 20 – 80 | 1 |
| Labetalol | Normodyne, Trandate | 200 – 800 | 2 |
| e. Cardioselective and vasodilatory beta-blockers | |||
| Nebivolol | Bystolic | 5 – 20 | 1 |
Some noted possible side effects of Beta-blockers
- Tiredness/fatigue
- Reduced exercise tolerance
- Bradycardia
- Cold peripheries
- Claudication
- Wheezing
- Impotence
3. Diuretics
Diuretics, also called water pills, are drugs that are used to facilitate elimination of extracellular fluid from the body. They exert their effect directly on the kidneys and reduce blood pressure by causing diuresis.
| Generic name | Common brand names | Usual dose range (mg/day) | Daily frequency |
| a. Thiazide diuretics | |||
| Chlorthalidone | Hygroton | 12.5–25 | 1 |
| Hydrochlorothiazide | Esidrix, HydroDiuril, Microzide, Oretic | 12.5–50 | 1 |
| Indapamide | Lozol | 1.25–2.5 | 1 |
| Metolazone | Zaroxolyn | 2.5–10 | 1 |
| b. Loop diuretics | |||
| Bumetanide | Bumex | 0.5–4 | 2 |
| Furosemide | Lasix | 20–80 | 2 |
| Torsemide | Demadex | 5–10 | 1 |
| c. Potassium-sparing diuretics | |||
| Amiloride | Midamor | 5–10 | 1 or 2 |
| Amiloride/ hydrochlorothiazide | Moduretic | 5–10/50–100 | 1 |
| Triamterene | Dyrenium | 50–100 | 1 or 2 |
| Triamterene/ hydrochlorothiazide | Dyazide | 37.5–75/25–50 | 1 |
Some noted possible side effects of diuretics
Thiazide diuretics
- Hypokalaemia
- Gout
- Glucose intolerance
- Hyperlipidaemia
- Impotence
- Uraemia
- Dehydration
Loop diuretics
- Dehydration
- Hypotension
- Electrolyte Imbalance ( e.g., hyponatremia, hypochloremia, hypokalemia, hypocalcemia, hypomagnesemia)
- Hyperglycemia
- Hyperuricemia
- Ototoxicity
Potassium sparing diuretics
- Headache
- Dizziness
- Nausea
- Skin rash
- Dry mouth
Read Also: Understanding the Various Types of Hypertension
4. Angiotensin II receptor blockers (ARBs)
ARBs modulate the Renin-Angiotensin-Aldosterone System (RAAS) by directly blocking the angiotensin II type 1 receptor site, preventing angiotensin II-mediated vasoconstriction and aldosterone release. Examples of ARBs include
| Generic name | Common brand names | Usual dose range (mg/day) | Daily frequency |
| Azilsartan | Edarbi | 40 – 80 | 1 |
| Candesartan | Atacand | 8 – 32 | 1 or 2 |
| Eprosartan | Teveten | 600 – 800 | 1 or 2 |
| Irbesartan | Avapro | 150 – 300 | 1 |
| Losartan | Cozaar | 50 – 100 | 1 or 2 |
| Olmesartan | Benicar | 20 – 40 | 1 |
| Telmisartan | Micardis | 20 – 80 | 1 |
| Valsartan | Diovan | 80 – 320 | 1 |
Some noted possible side effects of ARBs
- Headache
- Rash
- Renal failure
5. Calcium channel blockers (CCBs)
These medications cause relaxation of cardiac and smooth muscle by blocking voltage-sensitive calcium channels, thereby reducing entry of extracellular calcium into cells. This leads to vasodilation and a corresponding reduction in blood pressure.
The dihydropyridine group work almost exclusively on L-type calcium channels in the peripheral arterioles and reduce blood pressure by reducing total peripheral resistance. In contrast, the effect of verapamil and diltiazem are primarily on the heart, reducing heart rate and cardiac output. Examples of calcium channel blockers include
| Generic name | Common brand names | Usual dose range (mg/day) | Daily frequency |
| a. Dihydropyridine | |||
| Felodipine | Plendil | 5–20 | 1 |
| Isradipine | DynaCirc | 5–10 | 2 |
| Isradipine SR | DynaCirc SR | 5–20 | 1 |
| Nicardipine SR | Cardene SR | 60–120 | 2 |
| Amlodipine | Norvasc | 2.5–10 | 1 |
| Nifedipine long-acting | Adalat CC, Nifedical XL, Procardia XL | 10–40 | 1 |
| b. Non-dihydropyridine | |||
| Diltiazem sustained release | Cardizem SR | 180–360 | 2 |
| Diltiazem sustained release | Cardizem CD, Cartia XT, Dilacor XR, Diltia XT, Tiazac, Taztia XT | 120–480 | 1 |
| Diltiazem extended release | Cardizem LA | 120–540 | 1 (morning or evening) |
| Verapamil sustained release | Calan SR, Isoptin SR, Verelan | 180–480 | 1 or 2 |
| Verapamil controlled onset, extended release | Covera-HS | 180–420
| 1 (in the evening) |
| Verapamil chronotherapeutic oral drug absorption system | Verelan PM | 100–400 | 1 (in the evening) |
Some noted possible side effects of calcium channel blockers
Dihydropyridine
- Flushing
- Dizziness
- Ankle swelling
- Headache
Non-dihydropyridine
- Dizziness
- Bradycardia/heart block
- Constipation ( verapamil only)
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