Common uses

Treating supraventricular tachycardia, a rhythm disturbance of the heart. It is also used for controlling heart rate response to other rhythm disturbances, specifically, atrial fibrillation and flutter. It may also be used for other conditions as determined by your doctor.
Diltiazem is a calcium channel blocker. It works by slowing the electrical conduction in the heart, slowing heart rate, and/or normalizing heart rhythm.


Before using

Some medical conditions may interact with Diltiazem . Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have heart failure or have had a recent heart attack with lung congestion, heart block, low blood pressure, a very slow heart rate, or abnormal heart rhythm
• if you have kidney or liver disease
Some MEDICINES MAY INTERACT with Diltiazem . Tell your health care provider if you are taking any other medicines, especially any of the following:
• Cimetidine or protease inhibitors (eg, indinavir) because they may increase the actions and side effects of Diltiazem
• Rifampin because it may decrease the effectiveness of Diltiazem
• Amiodarone, cisapride, digoxin, erythromycin, protease inhibitors (eg, indinavir), quinidine, tricyclic antidepressants (eg, desipramine), theophylline, or general anesthetics because toxic effects on the heart may occur
• Benzodiazepines (eg, midazolam), beta-blockers (eg, metoprolol), buspirone, carbamazepine, cilostazol, corticosteroids (eg, prednisone), cyclosporine, HMG-CoA reductase inhibitors (eg, atorvastatin), macrolide immunomodulators (eg, tacrolimus) because the risk of their side effects, some potentially life-threatening, may be increased by Diltiazem
This may not be a complete list of all interactions that may occur. Ask your health care provider if Diltiazem may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

Directions

This medication should be swallowed whole with a full glass of water unless your doctor directs you otherwise. May be taken with or without meals. This drug must be taken as directed if used to prevent chest pain. It is not effective if taken only when chest pain occurs. Do not stop taking this medication suddenly without your doctor's permission. Your dose may need to be gradually decreased.

Cautions

If you are taking Diltiazem for high blood pressure, remember that it does not cure the problem; it merely controls it. You may need to take a blood pressure medication for the rest of your life.
If you are taking Diltiazem for angina, do not stop suddenly. This can lead to an increase in your attacks.

If you have congestive heart failure or suffer from kidney or liver disease, use Diltiazem with caution.
This medication may cause your heart rate to become too slow. You should check your pulse regularly.

Possible side effects

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 any of these serious side effects:
• fast or slow heartbeats;
• feeling light-headed, fainting;
• fever, sore throat, and headache with a severe blistering, peeling, and red skin rash;
• feeling short of breath, even with mild exertion;
• swelling, rapid weight gain; or
• nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).
Less serious side effects may include:
• stuffy nose;
• skin rash or itching;
• dizziness, headache, tired feeling;
• nausea; or
• warmth, itching, redness, or tingly feeling under your skin.


If you take too much

Seek emergency medical attention if you think you have used too much of this medicine.
Overdose symptoms may include slow heartbeat, weakness, chest pain, shortness of breath, feeling light-headed, or fainting.

Additional information

Diltiazem can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and 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. Do not increase or decrease the amount of grapefruit products in your diet without first talking to your doctor.


Drug interactions

Before taking diltiazem, tell your doctor if you are using any of the following drugs:
• amiodarone (Cordarone, Pacerone);
• buspirone (BuSpar);
• carbamazepine (Carbatrol, Tegretol);
• cimetidine (Tagamet, Tagamet HB);
• cyclosporine (Gengraf, Neoral, Sandimmune);
• digoxin (digitalis, Lanoxin, Lanoxicaps);
• lovastatin (Mevacor);
• rifampin (Rifadin, Rimactane, Rifater);
• quinidine (Quinaglute, Quinidex, Quin-Release);
• a sedative such as midazolam (Versed) or triazolam (Halcion);
• an antibiotic such as clarithromycin (Biaxin), erythromycin (E-Mycin, E.E.S., Ery-Tab, Erythrocin), fluconazole (Diflucan), itraconazole (Sporanox), ketoconazole (Nizoral), telithromycin (Ketek), or voriconazole (Vfend);
• a beta-blocker such as atenolol (Tenormin), bisoprolol (Zebeta, Ziac), metoprolol (Lopressor, Toprol), propranolol (Inderal, InnoPran), sotalol (Betapace), timolol (Blocadren), and others; or
• HIV/AIDS medicine such as amprenavir (Agenerase), atazanavir (Reyataz), delavirdine (Rescriptor), fosamprenavir (Lexiva), indinavir (Crixivan), nelfinavir (Viracept), or ritonavir (Norvir, Kaletra).