What is the most important information I should know about diltiazem?

Do not use this medication if you have certain heart conditions such as "sick sinus syndrome" or "AV block" (unless you have a pacemaker), low blood pressure, or if you have recently had a heart attack.

Before taking diltiazem, tell your doctor if you have kidney disease, liver disease, or congestive heart failure.

Diltiazem may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Do not stop taking this medication without first talking to your doctor. If you stop taking diltiazem suddenly, your condition may become worse.

Diltiazem may be only part of a complete program of treatment that also includes diet, exercise, and other medications. Follow your diet, medication, and exercise routines very closely.

If you are being treated for high blood pressure, keep using this medication even if you feel well. High blood pressure often has no symptoms.

What is diltiazem?

Diltiazem is in a group of drugs called calcium channel blockers. It works by relaxing the muscles of your heart and blood vessels.

Diltiazem is used to treat hypertension (high blood pressure), angina (chest pain), and certain heart rhythm disorders.

Diltiazem may also be used for purposes not listed in this medication guide.

What should I discuss with my healthcare provider before taking diltiazem?

You should not use this medication if you are allergic to diltiazem, or if you have:

• certain heart conditions, especially "sick sinus syndrome" or "AV block" (unless you have a pacemaker);
• low blood pressure; or
• if you have recently had a heart attack.

To make sure you can safely take diltiazem, tell your doctor if you have any of these other conditions:

• kidney disease;
• liver disease;
• congestive heart failure; or
• if you are also taking clonidine (Catapres).

FDA pregnancy category C. It is not known whether diltiazem will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

Diltiazem can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

How should I take diltiazem?

Take exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.

Your doctor may occasionally change your dose to make sure you get the best results.

Take diltiazem with a full glass of water.

Do not crush, chew, break, or open an extended-release tablet or capsule. Swallow it whole. Breaking or opening the pill may cause too much of the drug to be released at one time.

If you have trouble swallowing a diltiazem capsule whole, ask your doctor or pharmacist if it is safe for you to open the capsule and sprinkle the medicine into a spoonful of applesauce to make swallowing easier. Swallow this mixture right away without chewing. Do not save the mixture for later use. Discard the empty capsule.

Use diltiazem regularly to get the most benefit. Get your prescription refilled before you run out of medicine completely.

Do not stop taking this medication without first talking to your doctor. If you stop taking diltiazem suddenly, your condition may become worse.

If you are being treated for high blood pressure, keep using this medication even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.

Diltiazem may be only part of a complete program of treatment that also includes diet, exercise, and other medications. Follow your diet, medication, and exercise routines very closely.

To be sure this medicine is helping your condition and is not causing harmful effects, your blood pressure will need to be checked often. Your liver and kidney function may also need to be tested. Visit your doctor regularly.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of diltiazem can be fatal.

Overdose symptoms may include slow heartbeat, weakness, chest pain, shortness of breath, feeling light-headed, or fainting.

What should I avoid while taking diltiazem?

Diltiazem may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Avoid drinking alcohol while taking diltiazem.

Grapefruit and grapefruit juice may interact with diltiazem and lead to potentially dangerous effects. Discuss the use of grapefruit products with your doctor.

Avoid exposure to sunlight or tanning beds. Diltiazem can make you sunburn more easily. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

What are the possible side effects of diltiazem?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have a serious side effect such as:

• a red, blistering skin rash;
• swelling in your hands or feet;
• trouble breathing;
• slow heartbeats;
• dizziness, fainting, fast or pounding heartbeat;
• upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes); or
• severe skin reaction -- fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Less serious side effects may include:

• headache;
• dizziness, weakness, tired feeling;
• upset stomach, nausea;
• sore throat, cough, stuffy nose; or
• flushing (warmth, redness, or tingly feeling).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect diltiazem?

Tell your doctor about all other medicines you use, especially:

• amiodarone (Cordarone, Pacerone);
• buspirone (BuSpar);
• carbamazepine (Carbatrol, Tegretol);
• cimetidine (Tagamet);
• cyclosporine (Gengraf, Neoral, Sandimmune);
• digoxin (digitalis, Lanoxin, Lanoxicaps);
• quinidine (Quin-G);
• rifampin (Rifadin, Rimactane, Rifater);
• an antibiotic such as clarithromycin (Biaxin), dalfopristin/quinupristin (Synercid), erythromycin (E.E.S., EryPed, Ery-Tab, Erythrocin, Pediazole), or telithromycin (Ketek);
• antifungal medication such as itraconazole (Sporanox), ketoconazole (Extina, Ketozole, Nizoral, Xolegal), miconazole (Oravig), or voriconazole (Vfend);
• a beta-blocker such as atenolol (Tenormin, Tenoretic), carvedilol (Coreg), labetalol (Normodyne, Trandate), metoprolol (Dutoprol, Lopressor, Toprol), nadolol (Corgard), propranolol (Inderal, InnoPran), sotalol (Betapace), and others;
• cholesterol medications such as atorvastatin (Lipitor, Caduet), fluvastatin (Lescol), lovastatin (Mevacor, Altoprev, Advicor), pravastatin (Pravachol), rosuvastatin (Crestor), or simvastatin (Zocor, Simcor, Vytorin);
• HIV/AIDS medicine such as atazanavir (Reyataz), delavirdine (Rescriptor), fosamprenavir (Lexiva), indinavir (Crixivan), nelfinavir (Viracept), or ritonavir (Norvir, Kaletra); or
• a sedative such as midazolam (Versed) or triazolam (Halcion).

This list is not complete and other drugs may interact with diltiazem. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

Where can I get more information?

Your pharmacist can provide more information about diltiazem.