Detailed Drug Information:

DRUG CLASS AND MECHANISM: Diltiazem 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, diltiazem 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 blood pressure, whichreduces the burden on the heart as it pumps blood to the body. Reducingheart burden lessens the heart muscle's demand for oxygen, and furtherhelps to prevent angina in patients with coronary artery disease. For moredetailed information related to coronary artery disease, please read articles: Cholesterol andHeart Attack.Diltiazem can decrease electrical conduction in the heart and slow heartrate.

PREPARATIONS: tablets (30, 60, 90, and 120 mg.), sustainedrelease SR capsules (60, 90, and 120 mg), extended release CD capsules(120, 180, 240, and 300 mg)

STORAGE: Store at room temperature in tightly closed container.

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. Diltiazem is used for the treatment andprevention of angina resulting from coronary artery spasm, as well as fromexertion. Diltiazem is also used in the treatment of high blood pressure.By slowing electrical conduction in the heart, diltiazem has been used intreating abnormally fast heart rhythms, such as atrial fibrillation.

DOSING: Diltiazem may be taken with or without food. Sincediltiazem is excreted by the kidney and metabolized by the liver, dosagesmay need to be lowered in patients with liver or kidney dysfunction.

DRUG INTERACTIONS: Diltiazem slows heart electrical conduction,and can cause a dangerously slow heart rate in patients with existingelectrical conduction disease of the heart. Concurrent use of diltiazemwith a beta blocker (another class of medications that slow heart rate)can occasionally cause profound heart slowing. Diltiazem can aggravateheart failure and cause excessive lowering of blood pressure.

Administration of diltiazem with digoxin can increase digoxin bloodlevels. Therefore, blood levels of digoxin are usually monitored to avoidtoxicity. Similarly, concurrent administration of diltiazem with ananti-seizure medication carbamazepine (Tegretol) can increase blood levelsof the seizure medication, and occasionally lead to toxicity. Concurrentadministration of cimetidine (Tagamet) interferes with the liver breakdownof diltiazem, and significantly increases diltiazem blood levels.Therefore, cautious dosing is necessary when both medications areadministered. Safety in children has not been established.

PREGNANCY: Generally, diltiazem is avoided in pregnancy.

NURSING MOTHERS: Generally, diltiazem is avoided in nursingmothers.

SIDE EFFECTS: Side effects are generally mild and transient.Diltiazem can cause difficulty breathing or wheezing as a result ofworsening heart failure. It can cause dizziness, weakness or faintingbecause of slow heart rate or low blood pressure. Other side effectsinclude swelling of the lower extremities, rash, headache, andconstipation. Diltiazem can also cause mildly abnormal liver tests thatare generally reversible with discontinuation of the medication.