CARDIO: CCBs

Question 1

CCBs: INDICATIONS

Answer 1

• 1st/2nd line of HTN
• Stable Angina
• SV Arrthythmias (Diltiazem and verapamil)

Question 2

CCBs: MOA

Answer 2

• Decrease Ca2+ entry into the vascular and cardiac cells, reducing intracellular calcium concentration
• Causes relaxation and vasodilatation in arterial smooth muscle, lowering arterial pressure
• Reduce myocardial contractility
• Suppress cardiac conduction, particularly across AV node slowing ventricular rate
• Reduced cardiac rate, contractility, after load reduce myocardial oxygen demand, preventing ANGINA

=> Dihydropines, selective for vasculature

=> Non-dihydropines, selective for the heart (verapamil most selective)

Question 3

CCBs: ADVERSE EFFECTS

Answer 3

• Amlodipine and Nifedipine = Ankle swelling, flushing and headache, palpitations (caused by vasodilatation and compensatory tachycardia)
• Verapamil - constipation and less often bradycardia, heart block and cardiac failure
• Diltiazem = mixed vascular and cardiac actions

Question 4

CCBs: WARNINGS

Answer 4

V+D:

• poor left ventricular function as they can precipitate or worsen heart failure
• Avoid in people with AV nodal conduction delay in whom they may provoke complete heart block

A+N:

• Unstable Angina as vasodilatation causes a reflex increase in contractility and tachycardia which increase myocardial oxygen demand
• Severe aortic stenosis - can provoke collapse

Question 5

CCBs: INTERACTIONS

Answer 5

• V+D should not be prescribed with beta blockers

Question 6

CCBs: EXAMPLES

Answer 6

• Amlodipine
• Nifedipine
• Diltiazem
• Verapamil