Antihypertensive Drugs Classification

These are drugs used to lower BP in hypertension. Hypertension is a very common disorder, particularly past middle age. It is not a disease in itself, but is an important risk factor for cardiovascular mortality and morbidity.

The cutoff manometric reading between normotensives and hypertensives is arbitrary. For practical purposes ‘hypertension’ could be that level of BP at or above which long-term antihypertensive treatment will reduce cardiovascular mortality. WHO have defined it to be 140 mm Hg systolic and 90 mm Hg diastolic, though risk appears to increase even above 120/80 mm Hg. Epidemiological studies have confirmed that higher the pressure (systolic or diastolic or both) greater is the risk of cardiovascular disease.

Majority of cases are of essential (primary) hypertension, i.e. the cause is not known. Sympathetic and renin-angiotensin systems (RAS) may or may not be overactive, but they do contribute to the tone of blood vessels and c.o. in hypertensives, as they do in normotensives. Many antihypertensive drugs interfere with these regulatory systems at one level or the other.

Antihypertensive drugs, by chronically lowering BP, may reset the barostat to function at a lower level of BP.

CLASSIFICATION

Diuretics

Thiazides: Hydrochlorothiazide, Chlorthalidone, Indapamide
High ceiling:Furosemide, etc.
K+ Sparing: Spironolactone, Amiloride

ACE inhibitors

Captopril, Enalapril, Lisinopril, Perindopril, Ramipril, Fosinopril, etc.

Angiotensin (AT1 receptor) blockers

Losartan, Candesartan, Irbesartan, Valsartan, Telmisartan

Direct renin inhibitor

Aliskiren

Calcium channel blockers

Verapamil, Diltiazem, Nifedipine, Felodipine, Amlodipine, Nitrendipine, Lacidipine, etc.

β Adrenergic blockers

Propranolol, Metoprolol, Atenolol, etc

β + α Adrenergic blockers

Labetalol, Carvedilol

α Adrenergic blockers

Prazosin, Terazosin, Doxazosin, Phentolamine, Phenoxybenzamine

Central sympatholytics

Clonidine, Methyldopa

Vasodilators

Arteriolar: Hydralazine, Minoxidil, Diazoxide
Arteriolar + venous: Sodium nitroprusside