ANTIHYPERTENSIVE DRUGS

Hypertension is the most common cardiovascular condition. A persistent and sustained high blood pressure has damaging effects on the heart, brain, kidneys and eyes. Hypertension is generally classified into two types.

• Primary or essential hypertension: In more than 95% of cases, there is no specific underlying cause. These patients are said to have essential hypertension.
  
• Secondary hypertension, seen in about 5% of cases, can be due to specific disease or drug.

Table : Classification of BP for adults

• Systolic blood pressure (SBP) is the maximum pressure recorded during ventricular systole.
• Diastolic blood pressure (DBP) is the minimum pressure recorded during ventricular diastole.
• Pulse pressure (PP): SBP – DBP
• Mean arterial pressure (MAP): DBP + 1/3 PP.

Fig: Sites of action of the major groups of antihypertensive drugs

Classification:

1. ACE Inhibitors:

Captopril, Enalapril, Lisinopril, Ramipril, Benazepril

2. Angiotensin II – receptor antagonists:

Losartan, Candesartan, Irbesartan, Valsartan

3. Calcium channel Blockers (CCB):

Nifedipine SR, Amlodipine, Nicardipine, Nimodipine, Felodipine, Verapamil, Diltiazem.

4. Diuretics:

   1. Thiazides and related agents – Hydrochlorothiazide, Chlorthalidone.

   2. Loop diuretics: Furosemide, Bumetanide, Torsemide.

   3. Potassium sparing diuretics – Amiloride, Triamterene, Spironolactone

5. Sympatholytic drugs:

   1. Centrally acting agents: Clonidine, Methyldopa

   2. Ganglion blockers: Trimethaphan

   3. Neuronal blockers: Reserpine,

   4. Alpha Adrenergic blockers

• Nonselective: Phenoxybenzamine, Phentolamine
• Selective: Prazosin, Terazosin

5. Beta Adrenergic blockers: Propranolol, Atenolol, Metoprolol

6. Vasodilators:

1. Arteriolar – Hydralazine, Minoxidil, Diazoxide
   

2. Arterial and venodilator: Sodium Nitroprusside.

Category: Pharmacology Notes