How Do Non-Dihydropyridine Calcium Channel Blockers Work?

Nondihydropyridinecalcium channel blockersare a class of antiarrhythmic drugs used to treat tachydysrhythmias (abnormalcardiacrhythm with a rate greater than 100 beats per minute) andhypertension(high blood pressure). Nondihydropyridines are one of the different types ofcalciumchannel blockers; they act mainly on theheartwith less effect onbloodvessels. They have a greater depressive effect on cardiac conduction and contractility but are less potentvasodilatorsthan other types of calcium channel blockers (dihydropyridines).

Nondihydropyridines work by blocking the calcium channels presentintheheart muscleand reduce the influx of calcium intocardiac muscle细胞(细胞),导致下降heart rateand contractions of the heartmuscle.

Normally, the influx of calcium into cardiac myocytes increases the automaticity and conduction velocity ofpacemakercells, thereby increasing the heart rate. Calcium also increases the force ofcontractionof nonpacemaker cardiac myocytes, thereby increasing thestroke volume.

Nondihydropyridine calcium channel blockers are used to treat:

• Hypertension
• Tachydysrhythmias
• Angina(chest paincaused by lack ofoxygento the heart muscle)
• Atrial fibrillation(irregular and rapid heartbeats in the upper chambers of the heart)
• Atrialflutters (rapid contractions of the upper chambers of the heart)
• Paroxysmalsupraventricular tachycardia(abnormal heart rhythm with symptoms of regular but rapid heartbeat that starts and stops abruptly)
• Severekidneydisease
• Diabetic neuropathy(nervedamage caused bydiabetes)

Side effects of nondihydropyridine calcium channel blockers may include:

• Constipation
• Tiredness
• Reduced contractility of the heart
• Worsening ofcardiac output
• Bradycardia(low heart rate)
• Gingivalhyperplasia(overgrowthof gumtissuearound the teeth)
• Hyperprolactinemia (increase inserumprolactinlevels)
• Atrioventricularblock (heart blockcaused by impairment of electrical impulses traveling fromatriato other chambers of the heart)
• Cardiotoxicity

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with yourdoctororpharmacistto make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking yourmedicationand never change your dose or frequency without consulting your doctor.

Genericand brand names of nondihydropyridine calcium channel blockers drugs include:

• Dilatrate
• Diltiazem (Cardizem,Cardizem CD,Cardizem LA,CartiaXT, Dilacor,Dilacor XR, Dilt-CD, Diltazem, Diltazem CD, Diltia XT, Diltiaz, Diltiaz CD, Diltiaz SR, Diltiazem CD, Diltiazem SR, Taztia XT,Tiazac)
• Dilzem
• Verapamil(Calan,Calan SR, CoveraHS,Isoptin, Isoptin IV, Isoptin SR, Verap, Verapamil SR,Verelan,Verelan PM)