Antihypertensive drugs are used to treat hypertension, a disorder characterized by elevation in systolic blood pressure, diastolic blood pressure, or both.
According to the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, several classes of drugs have been shown in clinical trials to be effective in treating hypertension. Diuretics, primarily thiazide diuretics, are used as initial therapy in treating most patients with hypertension.
Classes of Antihypertensive drugs used to treat hypertension include:
• Angiotensin-converting enzyme (ACE) inhibitors
• Angiotensin-receptor blockers (ARBs)
• Beta-adrenergic antagonists
• Calcium channel blockers.
If these drugs are ineffective, treatment continues with sympatholytic drugs (other than beta-adrenergic blockers), direct vasodilators, selective aldosterone-receptor antagonists, or a combination of drugs.
Angiotensin-converting enzyme inhibitors:
ACE inhibitors reduce blood pressure by interrupting the reninangiotensin activating system (RAAS). Commonly prescribed ACE inhibitors include:
• Captopril (see ACE inhibitors: Captopril)
• Fosinopril sodium
ACE inhibitors are absorbed from the GI tract, distributed to most body tissues, metabolized somewhat in the liver, and excreted by the kidneys. Ramipril also is excreted in feces. Enalaprilat is the only IV ACE inhibitor available.
Side Effects of ACE inhibitors:
ACE inhibitors can cause these adverse reactions:
• Dry, nonproductive, persistent cough
• GI reactions
• Increased serum potassium concentrations
• Tickling in the throat
• Transient elevations of BUN and serum creatinine levels (indicators of kidney function).
They can cause problems with fetal circulation and shouldn’t be administered during the second or third trimester of pregnancy.
Beta-adrenergic antagonists, or beta-adrenergic blockers, are one of the main types of drugs used to treat hypertension, including ocular hypertension. They’re also used for long-term prevention of angina. Beta-adrenergic blockers used for hypertension include:
• Metoprolol tartrate
• Propranolol hydrochloride
Adverse reactions to beta-adrenergic blockers include:
• Bradycardia, angina, heart failure, and arrhythmias, especially AV block
• Fluid retention
• Peripheral edema
• Nausea and vomiting
• Significant constriction of the bronchioles.
Calcium channel blockers:
Calcium channel blockers are commonly used to treat hypertension. Several are also used to treat arrhythmias and to prevent angina that doesn’t respond to other antianginal drugs. Calcium channel blockers used to treat hypertension include:
• Amlodipine besylate
Possible adverse reactions include headache, dizziness, weakness, orthostatic hypotension, heart failure, hypotension, peripheral edema, palpitations, and arrhythmias such as tachycardia. Bradycardia and AV block also occur with diltiazem and verapamil.