Generic name: Diltiazem 12-Hour Sustained-Release Capsules [ dil-TYE-a-zem ]
Drug classes: Calcium channel blocking agents, Group IV antiarrhythmics

Medically reviewed by Drugs.com. Last updated on Mar 15, 2023.

Uses of Diltiazem 12-Hour Sustained-Release Capsules:

• It is used to treat high blood pressure.
• It may be given to you for other reasons. Talk with the doctor.

What do I need to tell my doctor BEFORE I take Diltiazem 12-Hour Sustained-Release Capsules?

• If you are allergic to this medicine (diltiazem 12-hour sustained-release capsules); any part of this medicine (diltiazem 12-hour sustained-release capsules); or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
• If you have certain types of abnormal heartbeats. There are many types of abnormal heartbeats with which this medicine (diltiazem 12-hour sustained-release capsules) must not be used. Ask your doctor or pharmacist if you are not sure.
• If you have any of these health problems: Fluid in the lungs, low blood pressure, or recent heart attack.
• If you are taking any of these drugs: Ivabradine or rifampin.

This is not a list of all drugs or health problems that interact with this medicine (diltiazem 12-hour sustained-release capsules).

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this medicine (diltiazem 12-hour sustained-release capsules) with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take Diltiazem 12-Hour Sustained-Release Capsules?

• Tell all of your health care providers that you take this medicine (diltiazem 12-hour sustained-release capsules). This includes your doctors, nurses, pharmacists, and dentists.
• Avoid driving and doing other tasks or actions that call for you to be alert until you see how this medicine (diltiazem 12-hour sustained-release capsules) affects you.
• To lower the chance of feeling dizzy or passing out, rise slowly if you have been sitting or lying down. Be careful going up and down stairs.
• Check blood pressure and heart rate as the doctor has told you.
• You may need to have an ECG checked before starting this medicine (diltiazem 12-hour sustained-release capsules) and while taking it. Talk with your doctor.
• If you are taking this medicine (diltiazem 12-hour sustained-release capsules) and have high blood pressure, talk with your doctor before using OTC products that may raise blood pressure. These include cough or cold drugs, diet pills, stimulants, ibuprofen or like products, and some natural products or aids.
• If you drink grapefruit juice or eat grapefruit often, talk with your doctor.
• Talk with your doctor before you drink alcohol.
• If you are 65 or older, use this medicine (diltiazem 12-hour sustained-release capsules) with care. You could have more side effects.
• Tell your doctor if you are pregnant, plan on getting pregnant, or are breast-feeding. You will need to talk about the benefits and risks to you and the baby.

How is this medicine (Diltiazem 12-Hour Sustained-Release Capsules) best taken?

Use this medicine (diltiazem 12-hour sustained-release capsules) as ordered by your doctor. Read all information given to you. Follow all instructions closely.

• Swallow whole. Do not chew, break, or crush.
• Take this medicine (diltiazem 12-hour sustained-release capsules) at the same time of day.
• Keep taking this medicine (diltiazem 12-hour sustained-release capsules) as you have been told by your doctor or other health care provider, even if you feel well.

What do I do if I miss a dose?

• Take a missed dose as soon as you think about it.
• If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
• Do not take 2 doses at the same time or extra doses.

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
• Very bad dizziness or passing out.
• Slow heartbeat.
• An abnormal heartbeat that is new or worse.
• Heart failure has gotten worse in some people taking this medicine (diltiazem 12-hour sustained-release capsules). If you have heart failure, talk with your doctor. Call your doctor right away if you have shortness of breath, a big weight gain, or swelling in the arms or legs.
• A very bad skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis) may happen. It can cause very bad health problems that may not go away, and sometimes death. Get medical help right away if you have signs like red, swollen, blistered, or peeling skin (with or without fever); red or irritated eyes; or sores in your mouth, throat, nose, or eyes.

What are some other side effects of Diltiazem 12-Hour Sustained-Release Capsules?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Headache.
• Feeling dizzy, tired, or weak.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

If OVERDOSE is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out Diltiazem 12-Hour Sustained-Release Capsules?

• Store at room temperature protected from light. Store in a dry place. Do not store in a bathroom.
• Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
• Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.

Consumer Information Use and Disclaimer

• If your symptoms or health problems do not get better or if they become worse, call your doctor.
• Do not share your drugs with others and do not take anyone else's drugs.
• Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about this medicine (diltiazem 12-hour sustained-release capsules), please talk with your doctor, nurse, pharmacist, or other health care provider.
• If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer