The main difference between dihydropyridine and nondihydropyridine CCB is that dihydropyridine CCB acts on smooth muscle cells, whereas nondihydropyridine CCB acts on the heart.
Dihydropyridine CCB and non-dihydropyridine CCB are two types of calcium channel blockers (CCBs). They bind and block L-type calcium channels, the type of predominant calcium channels in vascular smooth muscles and the heart.
Key Areas Covered
1. What is Dihydropyridine CCB
– Definition, Features, Importance
2. What is Non-dihydropyridine CCB
– Definition, Features, Importance
3. Similarities Between Dihydropyridine and Non-dihydropyridine CCB
– Outline of Common Features
4. Difference Between Dihydropyridine and Nondihydropyridine CCB
– Comparison of Key Differences
Key Terms
Dihydropyridine CCB, Non-dihydropyridine CCB
What is Dihydropyridine CCB
Dihydropyridine CCB is a type of calcium channel blocker that blocks calcium channels in muscle cells that occur in the heart and arterial blood vessels. The main function of a calcium channel blocker is to reduce the entry of calcium ions into the cell. This promotes blood vessel dilation or vasodilation while reducing the heart rate, strength of contractility, and speed of conduction within the heart. Additionally, the dilation of blood vessels causes a reduction in blood pressure, and it decreases the oxygen requirement of the heart. However, dihydropyridine CCB predominantly blocks calcium channels in blood vessels, causing vasodilation. Also, it has no direct effect on the function of the heart.
Figure 1: Amlodipine
Furthermore, dihydropyridine CCB is important for treating hypertension by dilating blood vessels. Also, dihydropyridines, like nifedipine, are important in treating high blood pressure in pregnant women. In contrast, long-acting dihydropyridine is important in treating vasospastic or Prinzmetal angina.
What is Non-dihydropyridine CCB
Nondihydropyridine CCB is the other type of calcium channel blocker. Also, it is an antiarrhythmic drug important in treating tachydysrhythmias, a condition of abnormal cardiac rhythm with greater than 100 beats per minute. It is also used to treat hypertension. The main significant feature of nondihydropyridine CCB is that they only act on the heart but are less effective on blood vessels. Therefore, nondihydropyridine CCB has a greater depressive effect on cardiac contractility and conduction. Importantly, it reduces the influx of calcium ions into cardiac muscle cells, decreasing heart rate and contraction.
Figure 2: Verapamil
Moreover, nondihydropyridine CCB is used to treat angina, arterial fibrillation, arterial flutters, paroxysmal supraventricular tachycardia, severe kidney disease, and diabetic neuropathy.
Similarities Between Dihydropyridine and Nondihydropyridine CCB
- Dihydropyridine and nondihydropyridine CCB are two types of calcium channel blockers.
- They block L-type calcium channels, the predominant type of calcium channels in the myocardium and vascular smooth muscles.
- They cause a drop in blood pressure and myocardial depression.
- They undergo peripheral arterial vasodilatation.
Difference Between Dihydropyridine and Nondihydropyridine CCB
Definition
Dihydropyridine CCB refers to a type of calcium channel blocker (CCB), which refer to a group of medications that block calcium channels located in the muscle cells, while non-dihydropyridine CCB refers to a class of antiarrhythmic drugs used to treat tachydysrhythmias (abnormal cardiac rhythm with a rate greater than 100 beats per minute) and hypertension (high blood pressure).
Effect
Dihydropyridine CCB acts on smooth muscle cells, while non-dihydropyridine CCB acts on the heart.
Effect on SVR (systemic vascular resistance)
Dihydropyridine CCB decreases SVR, while nondihydropyridine CCB decreases SVR slowly.
Effect on Contractility
Dihydropyridine CCB has no effect on contractility, while nondihydropyridine decreases contractility.
Effect on Sinus Node Rate
Dihydropyridine CCB has no effect on the sinus node rate, while nondihydropyridine slows the sinus node rate.
Effect on AV Node
Dihydropyridine CCB has no effect on the AV node, while nondihydropyridine CCB slows the AV node.
Examples
Amlodipine, Felodipine, Nifedipine, and Nicardipine are examples of dihydropyridine CCB while Diltiazem and Verapamil are examples of nondihydropyridine CCB.
Side Effects
Low blood pressure, headaches, dizziness, and facial flushing are the side effects of dihydropyridine CCB while constipation, tiredness, reduced contractility of the heart, worsening of cardiac output, bradycardia, gingival hyperplasia, hyperprolactinemia, atrioventricular block, and cardiotoxicity are the side effects of nondihydropyridine CCB.
Conclusion
In brief, dihydropyridine and nondihydropyridine CCB are two types of calcium channel blockers. They block the L-type calcium channels, which are the predominant type of calcium channels. Dihydropyridine CCB acts on the smooth muscle cells. They decrease SVR. Examples of dihydropyridine CCB are Amlodipine, Felodipine, Nifedipine, and Nicardipine. In comparison, nondihydropyridine CCB acts on the heart. Also, it decreases SVR slowly. Additionally, it decreases the contractility, sinus node rate, and AV node rate. Diltiazem and Verapamil are examples of nondihydropyridine. Therefore, the main difference between dihydropyridine and nondihydropyridine is the effect on the body.
References:
- Dihydropyridines: What are they, mechanism of action – osmosis. (n.d.-b).
- Sruthi M., M. (2021, June 22). How do non-dihydropyridine calcium channel blockers work? uses, side effects, drug names. RxList.
Image Courtesy:
- “Amlodipine” By Fvasconcellos– Own work (Public Domain) via Commons Wikimedia
- “Verapamil skeletal” By DoSiDo – Own Work (Public Domain) via Commons Wikimedia
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