Calcium channel blockers (CCB’s) – (calcium antagonists):
Drugs that prevent calcium ions from entering cells decrease in afterload by relaxing vascular smooth muscle and cause vasodilaton
Used to treat hypertension (moderate to severe), angina pectoris and dysrhythmias
Calcium channels are gated pores in cytoplasmic membrane – role is to regulate the movement of calcium ions into the cells play role in initiating contractile process of smooth muscle. If channels blocked contraction prevented vasodilation
Three types:
• dihydropyridines (eg nifedipine, amlodipine, felodipine) – act primarily on arterioles
• phenylakylamines (eg verapamil) – act on arterioles and heart
• benzothiazepines (eg diltiazem) – act on arterioles and heart
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