Calcium channel blockers are medications used to treat high blood pressure, heart rhythm disturbances, and angina pectoris (chest pain). Calcium channel blockers are so named because they close off the channels in the cell membrane that allow calcium to return to the cell after contraction. They relax the blood vessels of the heart, allowing increased blood flow and relieving angina pain. They also slow the rate at which electrical impulses are conducted, so the heart rate is slowed.
Calcium channel blockers
Brand/Generic Drug Names
Cardizem/diltiazem, felodipine, nicardipine, Procardia/nifedipine, Calan/verapamil
Common uses
chronic stable angina pectoris, vasospastic angina, dysrhythmias, hypertension, unstable angina
Pharmacology
inhibit calcium ion influx across cell membrane in cardiac and vascular smooth muscle, producing coronary artery vasodilation, peripheral artery vasodilation, and slowing SA/AV node conduction
Class contraindications
2nd/3rd degree heart block, sick sinus syndrome, hypotension <90 mmHg systolic, Wolff-Parkinson-White syndrome, cardiogenic shock
Class precautions
congestive heart failure, hypotension, renal and liver disease
Interactions
Increased levels: digoxin, theophylline
Increased effect: beta-blockers, antihypertensives
Adverse Reactions
dysrhythmias, edema, headache, fatigue, drowsiness, flushing
Additional Information
Assess cardiac status (blood pressure, pulse, respirations, ECG intervals)
Evaluate therapeutic response: decreased anginal pain, blood pressure, dysrhythmias
Date of most recent Update
September 04, 2002
Further information is available in the writeup for the
specific name(s) of this medication class