Antihypertensive Drugs Overview Quiz

Antihypertensive Drugs: An Overview

Antihypertensive medications help lower blood pressure (BP) to reduce the risk of cardiovascular diseases and stroke. They fall into several classes, each offering distinct mechanisms of action and potential side effects.

Types of Antihypertensive Drugs

• Angiotensin-Converting Enzyme (ACE) inhibitors: Block the conversion of angiotensin I to angiotensin II, leading to vasodilation. Examples include lisinopril and enalapril.
• Angiotensin II Receptor Blockers (ARBs): Prevent angiotensin II from binding to its receptor, also causing vasodilation. Examples include losartan and valsartan.
• Calcium Channel Blockers (CCBs): Prevent calcium from entering smooth muscle cells, relaxing blood vessels. Examples include amlodipine and verapamil.
• Diuretics: Help the kidneys remove excess sodium and water from the body, reducing blood volume and BP. Examples include furosemide and hydrochlorothiazide.
• Beta-blockers: Reduce heart rate and cardiac output, thereby lowering BP. Examples include atenolol and metoprolol.
• Central acting agents: Act on the central nervous system to reduce BP. Example: clonidine.
• Peripheral adrenergic inhibitors: Block the release of norepinephrine from nerve endings, reducing BP. Example: reserpine.

Mechanism of Action

• ACE inhibitors and ARBs: Lower BP by reducing the effects of angiotensin II, which leads to vasodilation and decreased aldosterone secretion.
• CCBs: Facilitate the relaxation of blood vessels by inhibiting calcium influx into the muscle cells of blood vessel walls.
• Diuretics: Lower BP by reducing blood volume through an increase in urine output.
• Beta-blockers: Lower BP by decreasing heart rate and cardiac output.
• Central acting agents: Lower BP via central nervous system mechanisms.
• Peripheral adrenergic inhibitors: Lower BP by blocking the release of norepinephrine from nerve endings.

Common Side Effects

• ACE inhibitors: Hypokalemia (low potassium levels), hyperkalemia (high potassium levels), angioedema, and kidney impairment
• ARBs: Hypokalemia, hyperkalemia, and kidney impairment
• CCBs: Headache, constipation, dizziness, and peripheral edema
• Diuretics: Increased urination, dehydration, electrolyte imbalances, and gout
• Beta-blockers: Fatigue, cold extremities, slowed heart rate, and reduced exercise ability
• Central acting agents: Dry mouth, dizziness, drowsiness, and depression
• Peripheral adrenergic inhibitors: Dizziness, dry mouth, postural hypotension, and sedation

Indications and Drug Interactions

• ACE inhibitors and ARBs: Used for heart failure, diabetic nephropathy, and proteinuria in nondiabetic chronic kidney disease
• CCBs: Used for hypertension, angina, and vasospastic disorders
• Diuretics: Used for hypertension, edema, and fluid retention
• Beta-blockers: Used for angina, heart failure, and arrhythmias
• Central acting agents: Used for hypertension, migraine, and anxiety disorders
• Peripheral adrenergic inhibitors: Used for hypertension and migraine

Drug interactions should be considered when prescribing antihypertensive medications. Some antihypertensive drugs may interact with medications for depression, erectile dysfunction, and immunosuppression.