PEBC: What You Need to Know: Calcium Channel Blockers

Two Classes:

1) Dihydropyridine (DHP): amlodipine, felodipine, nifedipine

2) Non-Dihydropyridine (Non-DHP): diltiazem, verapamil

Indications:

-Hypertension

-Heart rate control (Non-DHP)

-Raynaud's Syndrome (DHP)

-migraine prophylaxis (verapamil)

Major Action:

Dihydropyridine: peripheral vasodilation

Non-Dihydropyridine: heart rate and contractility reduction - avoid in heart failure

Adverse Effects:

-flushing

-peripheral edema (DHP)

-bradycardia (Non-DHP)

-constipation (verapamil)

Drug Interactions:

-All CYP3A4 substrates: avoid grapefruit juice and inhibitors

-Verapamil and diltiazem are CYP3A4/pg-p inhibitors themselves, so caution with other agents (especially newer oral anticoagulants like apixaban, rivaroxaban)

-Non-DHP: caution with other heart rate lowering medications such as beta-blockers, digoxin, amidarone