All are dihydropyradines except
**Core Concept**
Dihydropyridines are a class of calcium channel blockers that selectively inhibit the L-type calcium channels in smooth muscle cells, leading to vasodilation. They are commonly used in the treatment of hypertension and angina pectoris.
**Why the Correct Answer is Right**
The correct answer is a dihydropyridine calcium channel blocker, which works by binding to the L-type calcium channels in the vascular smooth muscle cells. This binding inhibits the influx of calcium ions, leading to vasodilation and a decrease in blood pressure. The dihydropyridine class includes drugs such as nifedipine, amlodipine, and felodipine.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is a class of calcium channel blockers that includes dihydropyridines. The correct dihydropyridine is not specified, but this option is still incorrect because it is a dihydropyridine.
**Option B:** This option is incorrect because it is a class of calcium channel blockers that includes dihydropyridines, such as diltiazem and verapamil. These drugs are not dihydropyridines.
**Option C:** This option is incorrect because it is a class of beta blockers, which work by blocking beta-adrenergic receptors in the heart. They are not dihydropyridines.
**Clinical Pearl / High-Yield Fact**
Dihydropyridines are commonly used in the treatment of hypertension and angina pectoris, but they can cause reflex tachycardia due to the vasodilation-induced decrease in blood pressure.
**Correct Answer: D. This option is not specified, but it is a dihydropyridine calcium channel blocker.**