Calcium channel blockers (CCBs) are used in the control and management of angina, hypertension and arrhythmias, such as supraventricular tachycardia. The three classes of calcium channel blockers are represented by verapamil (phenylalkylamine), diltiazem (benzothiazepine) and nifedipine (dihydropyridine). The pharmacologic effect is different for each.
Dihydropyridines
Dihydropyridines are a type of calcium channel blocker that targets the smooth cardiac muscle to lower arterial pressure and systemic vascular resistance. This is a primary medication in the treatment of high blood pressure (hypertension). Dihydropyridines are not as effective in treating angina (pain) as other types of calcium channel blockers.
More Dihydropyridines
Amlodipine (Norvasc), nifedipine (Procardia XL, Adalat CC), felodipine (Plendil), nimodipine (Nimotop) and isradipine (Dynacirc, Dynacirc CR) are in the dihydropyridine type of CCBs. These drugs ease the load of the heart by widening blood vessels.
Phenylalkylamines
Phenylalkylamines are one of the two non-dihydropyridine calcium channel blockers. These drugs are more directed at relaxing the heart muscles and less directed as a systemic vasodilator drug. They are used for control of angina (chest pain caused by reduced blood supply to the heart muscle) and arrhythmias (irregular heart rhythms).
Phenylalkylamines
Verapamil, a phenylalkylamine, is a non-dihydropyridine sold under the brand names of Calan, Calan SR, Covera-HS, Isoptin SR, Verelan, Verelan PM and Isoptin. It should not be taken if you have low blood pressure or have recently had a heart attack.
Benzothiazepines
Diltiazem, a benzothiazepine, is a type of calcium channel blocker that's a mix between verapamil and nifedipine. It's a cardiac depressant that acts as a vasodilator. It may be used alone or with other medicines to treat the symptoms of angina or high blood pressure. This drug is available as Cardizem CD, Cartia XT, Dilacor XR, Diltia XT, Dilt CD, Diltzac, Taztia XT and Tiazac.
Dihydropyridine Side Effects
Dihydropyridine calcium channel blockers may have side effects such as headache, excessively low blood pressure, flushing, edema (swelling) and rapid heart rate. Use these with caution when combined with other heart medications such as beta blockers and ranitidine. Dosage may need to be adjusted to avoid elevated levels.
Non-dihydropyridine Verapamil
Non-dihydropyridine calcium channel blockers are not recommended for patients with heart failure or bradycardia (slow heart rate). Verapamil dosage may be lowered for patients taking beta blockers. Grapefruit and grapefruit juice should be avoided while taking verapamil without discussing this with your doctor or pharmacist.
Non-dihydropyridine Diltiazem
Diltiazem is not recommended for patients with ventricular tachycardia, a recent heart attack or heart conditions such as "sick sinus syndrome" (a group of heart rhythm problems affecting the sinus node).
