How Are Calcium Channel Blockers Classified, and Do They Have Any Side Effects?

Calcium channel blockers are a diverse group of drugs that can be used to treat various conditions such as angina pectoris, hypertension, and arrhythmias. It is crucial to have a general understanding of the classification of these drugs, as well as the characteristics and usage of each drug, to ensure their effective utilization. In this article, we will explore the classification of calcium channel blockers, their indications, and potential side effects.

Calcium channel blockers can be classified into several categories based on their selectivity for slow calcium channels.

(1) Selective Calcium Channel Blockers for Slow Channels (3 Classes):

• Benzalkonium derivatives: Clinically used as verapamil.
• Dihydropyridine derivatives: Clinically used drugs include nifedipine, felodipine, nimodipine, nicardipine, and amlodipine.
• Benzothiazepine derivatives: Clinically used as diltiazem.

(2) Non-Selective Calcium Channel Blockers for Slow Channels (2 Classes):

• Diphenylbutylpiperazine derivatives: Clinically used drugs include cinnarizine and flunarizine.
• Pranidipine derivatives: Including pranidipine and fendiline.

(3) Others: Including caroverine and fluspirilene used for the treatment of mental illness. Additionally, traditional Chinese medicines such as berberine and danshen also possess calcium channel blocking effects.

Calcium channel blockers are clinically used in the prevention and treatment of cardiovascular and cerebrovascular diseases.

1. Angina Pectoris: These drugs have varying degrees of effectiveness in treating various types of angina pectoris.

2. Arrhythmia: They are effective in treating supraventricular tachycardia and arrhythmias triggered by post-repolarization activities.

3. Hypertension: Drugs such as nifedipine, amlodipine, and felodipine have strong vasodilatory effects and are used to control severe hypertension symptoms. Verapamil and diltiazem can be used for mild to moderate hypertension.

4. Cerebrovascular Diseases: Some drugs, such as nimodipine, can significantly dilate cerebral vessels and increase cerebral blood flow, making them useful in the treatment of transient ischemic attacks, cerebral thrombosis, and cerebral embolism.

5. Others: Calcium channel blockers can also be used in the treatment of peripheral vasospasm, bronchial asthma, and migraine.

Common adverse reactions to calcium channel blockers include flushing, headache, nausea, and hypotension. Hypotension is more common when the dose is excessive or when used concurrently with other antihypertensive drugs. Peripheral edema is a common adverse effect, particularly with dihydropyridine derivatives, and is most frequently observed in the ankles but can also occur in the hands. Constipation is commonly seen with non-dihydropyridine drugs such as verapamil and diltiazem, and its severity is positively correlated with the drug dosage.