Advantages Of Calcium Channel Blockers

Advantages Of Calcium Channel Blockers

Question 1. Describe Briefly The Role Of Thiazides And Calcium Channel Blockers In the Management Of Hypertension.
Answer:

Role Of Thiazides In The Management Of Hypertension

Thiazides are used in the management of uncomplicated mild to moderate hypertension.

If chronic therapy of thiazide is given to the patient there is a decrease in sodium concentration in vascular smooth muscle which causes a decrease in pulmonary venous return and this leads to a decrease in blood pressure.

Along with thiazides, potassium-sparing diuretics should be given to counteract potassium loss and increase antihypertensive efficacy.

Role Of Calcium Channel Blockers In The Management Of Hypertension

• Calcium channel blockers lead to the dilatation of the arterioles which causes a decrease in peripheral vascular resistance. Examples are verapamil, diltiazem, and dihydropyridines.
• In calcium channel blockers dihydropyridines are the preferred drugs due to their selective action over blood vessels. Examples of dihydropyridines are nifedipine, amlodipine, felodipine, etc. These drugs reduce total peripheral resistance.
• Nifedipine causes reflex tachycardia. For counteracting reflex tachycardia β blockers are given with nifedipine. Nifedipine is given sublingually and is used in cases of hypertensive emergency.
• Verapamil decreases the force of contraction and decreases heart rate which reduces the oxygen requirement of the myocardium. This leads to a decrease in blood pressure.

Question 2. Classify Advantages Of Calcium Channel Blockers.
Answer:

Advantages Of Calcium Channel Blockers

• All calcium channel blockers are effective antihypertensive agents because of peripheral vasodilator activity. Blood pressure reduction appears to be more marked in those with low renin hypertension.
• Calcium channel blockers combine well with drugs that block the renin-angiotensin system (ACE inhibitors and angiotensin receptor blockers) to produce overall antihypertensive effects.
• Dihydropyridine calcium channel blockers are particularly useful in elderly patients with isolated systolic hypertension.
• Calcium channel blockers are efficacious, especially for isolated systolic hypertension.
• Calcium channel blockers have a lower incidence of side effects when compared to many older antihypertensive drugs.
• They are alternative agents in the treatment of chronic stable angina in patients without contraindications, who do not respond adequately to or tolerate, nitrates and α-blockers.
• Angina is secondary to coronary artery spasm and may respond particularly well to verapamil, diltiazem, or nifedipine.