Calcium channel blockers used in HTN are all except:
**Calcium Channel Blockers in Hypertension**
**Core Concept**
Calcium channel blockers (CCBs) are a class of antihypertensive medications that inhibit the influx of calcium ions into vascular smooth muscle cells, leading to vasodilation and reduced blood pressure. These medications are used to treat hypertension and certain cardiac arrhythmias.
**Why the Correct Answer is Right**
Calcium channel blockers work by blocking the L-type calcium channels on the surface of vascular smooth muscle cells. This blocks the influx of calcium ions, which are necessary for muscle contraction. As a result, blood vessels relax, and blood pressure decreases. Common calcium channel blockers used in hypertension include:
* Amlodipine (a dihydropyridine CCB)
* Verapamil (a non-dihydropyridine CCB)
* Diltiazem (a non-dihydropyridine CCB)
**Why Each Wrong Option is Incorrect**
**Option A:** Is a correct calcium channel blocker, a dihydropyridine CCB commonly used in hypertension.
**Option B:** Is a correct calcium channel blocker, a non-dihydropyridine CCB commonly used in hypertension.
**Option D:** Is a correct calcium channel blocker, a non-dihydropyridine CCB commonly used in hypertension.
**Clinical Pearl / High-Yield Fact**
When choosing a calcium channel blocker for a patient with hypertension, consider the patient's underlying cardiac disease. Non-dihydropyridine CCBs (verapamil and diltiazem) are more likely to exacerbate heart failure, whereas dihydropyridine CCBs (amlodipine) are generally safer in this population.
**Correct Answer:** A.