Detailed Drug Information:

DRUG CLASS AND MECHANISM: Nifedipine belongs to a class ofmedications called calcium channel blockers. These medications block thetransport of calcium into the smooth muscle cells lining the coronaryarteries and other arteries of the body. Since calcium is important inmuscle contraction, blocking calcium transport relaxes artery muscles anddilates coronary arteries and other arteries of the body. By relaxingcoronary arteries, nifedipine is useful in treating and preventing chestpain (angina) resulting from coronary artery spasm. Relaxing the muscleslining the arteries of the rest of the body lowers the blood pressure,which reduces the burden on the heart as it pumps blood to the body.Reducing heart burden lessens the heart muscle's demand for oxygen, andfurther helps to prevent angina in patients with coronary artery disease.For more detailed information related to coronary artery disease, pleasevisit the Chest Pain,Cholesterol, andHeart Attack articles.

PREPARATIONS: 10mg and 20mg capsules. Also available in extended release forms(Procardia XL, Adalat CC)in 30, 60,and 90mg capsules

STORAGE: Store at room temperature, avoid light and moisture.

PRESCRIBED FOR: Chest pain (angina) occurs because ofinsufficient oxygen delivered to the heart muscles. Insufficient oxygenmay be a result of coronary artery blockage or spasm, or because ofphysical exertion which increases heart oxygen demand in a patient withcoronary artery narrowing. Nifedipine is used for the treatment andprevention of angina resulting from coronary artery spasm as well as fromexertion. Nifedipine is also used in the treatment of high blood pressure.It is also used to open the blood vessels which spasm, causing Raynaud'sphenomenon.

DOSING: Nifedipine can be taken with or without food. Nifedipineis metabolized mainly by the liver and dosages may need to be lowered inpatients with liver dysfunction.

DRUG INTERACTIONS: In patients with severe obstructive coronaryartery disease, nifedipine can increase the frequency and severity ofangina or actually cause a heart attack on rare occasions. This phenomenonusually occurs when first starting nifedipine, or at the time of dosageincrease. Excessive lowering of blood pressure during initiation ofnifedipine treatment can occur, especially in patients already takinganother blood pressure lowering medication. In rare instances, congestive heart failure has been associated with nifedipine, usually in patientsalready on a beta blocker.

Administration of nifedipine with digoxin can increase digoxin bloodlevels. Therefore, blood levels of digoxin are usually monitored to avoidtoxicity. Concurrent administration of cimetidine (Tagamet) interfereswith the liver breakdown of nifedipine, and significantly increasesnifedipine blood levels. Therefore, cautious dosing is necessary when bothmedications are administered. Generally, nifedipine is avoided inchildren.

PREGNANCY: Generally, nifedipine is avoided during pregnancy.

NURSING MOTHERS: Generally, nifedipine is avoided in nursingmothers.

SIDE EFFECTS: Side effects of nifedipine are generally mild, andreversible. Most side effects are expected consequences of the dilation ofthe arteries. The most common side effects of nifedipine include headache,dizziness, flushing, and edema (swelling) of the lower extremities. Lesscommon side effects include dizziness, nausea and constipation.