Question

Complete a concept map for antihypertensive drugs.

Answer 1

Answer: Antihypertensive drugs are used in high blood pressure. These drugs can be classified into:

Classification of Antihypertensive drugs:
1. Diuretics:
Types

• Thiazides and related diuretics.
• Loop diuretics.
• Potassium sparing diuretics.

Mechanism of Action

It mainly acts through reduction of plasma volume and cardiac output and for long term action through a decrease in total peripheral vascular resistance.

2. Beta adrenergic blockers.

Mechanisms of Action:

Initially it decreases cardiac output, followed by reduction in peripheral vascular resistance. Other actions include decrease plasma renin activity, resetting of baroreceptors, release of vasodilator prostaglandins, and blockade of prejunctional beta-receptors.

3. Calcium channel blockers. :Phenylalkylamine: verapamil.

Mechanism of action:

It acts by decreasing the concentration of free intracellular calcium ions results in decreased contraction and vasodilation.

4. Angiotensin converting enzyme inhibitors.

Types;

Class I: captopril
Class II (prodrug) : e.g., ramipril, enalapril, perindopril
Class III ( water soluble) : lisinopril.

Mechanism of action:

• Inhibition of circulating and tissue angiotensin- converting enzyme.
• Increased formation of bradykinin and vasodilatory prostaglandins.
• Decreased secretion of aldosterone; help sodium excretion.

Side Effects

• Bronchospasm and obstructive airway disease.
• Bradycardia
• Metabolic effects (raise triglyerides levels and decrease HDL cholesterol; may worsen insulin
• sensitivity and cause glucose intolerance). Increased incidence of diabetes mellitus.