What are the major groups of antihypertensive drugs mentioned in the chapter, and how do they primarily affect blood pressure?

The major groups of antihypertensive drugs include angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor antagonists, alpha-adrenergic antagonists, beta-adrenergic blockers, combined alpha and beta antagonists, calcium channel antagonists, diuretics, peripheral vasodilators, and centrally acting sympathetic nervous system depressants. These drugs primarily affect blood pressure by lowering systemic vascular resistance (SVR) or cardiac output, thereby reducing overall blood pressure levels.

Antihypertensive drugs are categorized into several major groups, each with distinct mechanisms of action. ACE inhibitors, alpha antagonists, and peripheral vasodilators primarily lower systemic vascular resistance (SVR). Diuretics reduce blood pressure by decreasing cardiac output. Beta-blockers, calcium channel antagonists, angiotensin II antagonists, and combined alpha and beta antagonists lower both cardiac output and SVR. This multifaceted approach helps in managing hypertension effectively.