Why is this medication prescribed?
Diltiazem is used to treat high blood pressure and to control angina (chest pain). Diltiazem is in a class of medications called calcium-channel blockers. It works by relaxing the blood vessels so the heart does not have to pump as hard. It also increases the supply of blood and oxygen to the heart.
High blood pressure is a common condition, and when not treated it can cause damage to the brain, heart, blood vessels, kidneys, and other parts of the body. Damage to these organs may cause heart disease, a heart attack, heart failure, stroke, kidney failure, loss of vision, and other problems. In addition to taking medication, making lifestyle changes will also help to control your blood pressure. These changes include eating a diet that is low in fat and salt, maintaining a healthy weight, exercising at least 30 minutes most days, not smoking, and using alcohol in moderation.
How should this medicine be used?
Diltiazem comes as a tablet, an extended-release (long-acting) tablet, and an extended-release capsule to take by mouth. The regular tablet is usually taken three or four times a day. The extended-release capsule and tablet are usually taken one or two times a day. Ask your pharmacist if you should take diltiazem with or without food, because instructions may vary with each product. Take diltiazem at around the same time(s) every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take diltiazem exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Swallow the extended-release capsules and tablets whole; do not chew or crush them.
Your doctor will probably start you on a low dose of diltiazem and gradually increase your dose, not more than once every 7 to 14 days if you are taking the extended-release tablet or capsule and not more than once every 1 to 2 days if you are taking the regular tablet.
If taken regularly, diltiazem may control chest pain, but it does not stop chest pain once it starts. Your doctor may give you a different medication to take when you have chest pain.
Diltiazem controls high blood pressure and chest pain (angina) but does not cure them. It may take up to 2 weeks before you feel the full benefit of diltiazem. Continue to take diltiazem even if you feel well. Do not stop taking diltiazem without talking to your doctor.
Other uses for this medicine
Diltiazem is also sometimes used to treat certain types of arrhythmias (abnormal heart rhythms). Talk to your doctor about the risks of using this medication for your condition.
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
What special precautions should I follow?
Before taking diltiazem,
- tell your doctor and pharmacist if you are allergic to diltiazem, any other medications, or any of the ingredients in diltiazem. Ask your pharmacist for a list of the ingredients.
- tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: atazanavir (Reyataz); benzodiazepines such as midazolam (Versed) and triazolam (Halcion); beta blockers such as atenolol (Tenormin, in Tenoretic), labetalol, metoprolol (Lopressor, Toprol XL, in Dutoprol), nadolol (Corgard, in Corzide), and propranolol (Inderal, Innopran, in Inderide); buspirone; carbamazepine (Carbatrol, Epitol, Equetro, Tegretol); cimetidine (Tagamet); cyclosporine (Gengraf, Neoral, Sandimmune); digoxin (Lanoxin); lovastatin (Altoprev, Mevacor, in Advicor); quinidine (in Nuedexta); and rifampin (Rifadin, in Rifamate, in Rifater, Rimactane). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with diltiazem, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
- tell your doctor if you have or have ever had a myocardial infarction (MI); a narrowing or blockage of your digestive system or any other condition that causes food to move through your digestive system more slowly; low blood pressure; or heart, liver, or kidney disease.
- tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking diltiazem, call your doctor.
- if you are having surgery, including dental surgery, tell your doctor or dentist that you are taking diltiazem.
What special dietary instructions should I follow?
If your doctor prescribes a low-salt or low-sodium diet, follow these directions carefully.
What should I do if I forget a dose?
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
What side effects can this medication cause?
Diltiazem may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- dizziness or lightheadedness
- slow heartbeat
- nasal congestion
Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately or get emergency medical treatment:
- swelling of the face, eyes, lips, tongue, hands, arms, feet, ankles, or lower legs
- difficulty breathing or swallowing
- yellowing of the skin or eyes
- extreme tiredness
- unusual bleeding or bruising
- lack of energy
- loss of appetite
- pain in the upper right part of the stomach
- flu-like symptoms
- increase in frequency or severity of chest pain (angina)
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).
What should I know about storage and disposal of this medication?
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
Symptoms of overdose may include the following:
- slow, fast, or irregular heartbeat
- difficulty breathing
- increased sweating
What other information should I know?
Keep all appointments with your doctor and the laboratory. Your blood pressure should be checked regularly to determine your response to diltiazem.
Your doctor may ask you to check your pulse (heart rate) daily and will tell you how fast it should be. If your pulse is slower than it should be, call your doctor for directions on taking diltiazem that day. Ask your doctor or pharmacist to teach you how to check your pulse.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
Brand names of combination products
- Teczem® (containing Diltiazem, Enalapril)¶
¶ This branded product is no longer on the market. Generic alternatives may be available.