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Clinical pharmacy 2024/2025 Level 3 Pharm D Pharmacology 1 (PO 502)

General Character of Calcium channel blocker

➢ block the inward movement of calcium by binding to L-type calcium
channels in the heart and in smooth muscle of the coronary and
peripheral arteriolar
Actions
➢ Calcium channel blockers do not dilate veins (not affect preload)
➢ vascular smooth muscle relaxes ➔ dilating mainly arterioles
↓ afterload

➢ Black hypertensive patients respond well to calcium channel blockers
➢ Most of these agents have short half-lives (3-8 hours) following an
oral dose.

Pharmacokinetics ➢ Sustained-release preparations are available and permit once daily
dosing.
 Amlodipine ➔ very long half-life ➔ not require a sustained-release
formulation

1) Intrinsic natriuretic effect ➔ don’t require the addition of a diuretic.
Advantages 2) Useful in the treatment of hypertensive patients who also have
asthma, diabetes, angina, and/or peripheral vascular disease.

➢ Dizziness, headache, and a feeling of fatigue (caused by ↓ in blood
pressure
S/E
➢ Nifedipine has caused gingival enlargement.
➢ Verapamil not used in CHF ➔ as it decreases contractility

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