In this drug factsheet:
How does this medication work? What will it do for me?
Diltiazem belongs to a family of medications known as calcium channel blockers. It is used alone or with other medications to treat high blood pressure and angina (chest pain). It works by relaxing blood vessels and by reducing the workload of the heart. The injectable form of this medication is sometimes used in the hospital to bring abnormal heart rhythms under control.
This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.
Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.
Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.
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How should I use this medication?
The recommended dose of diltiazem can range from 30 mg to 360 mg daily. The dose for the tablet form of diltiazem is usually taken 3 or 4 times a day. The dose for the capsule form of diltiazem is usually taken once daily. Swallow the capsules whole with fluids. Do not chew, or crush , or open the capsules.
The starting dose of diltiazem to treat angina is usually 120 mg to 180 mg daily. Depending on how well the medication is tolerated and how effective it is at this dose, your doctor may gradually increase the dose every 1 to 2 weeks to a maximum of 360 mg daily.
The starting dose to treat high blood pressure is usually 180 mg to 240 mg daily. It may take 2 to 4 weeks to reach a maximum benefit with any one dose, therefore dose increases should not be done more often than every 2 weeks, to a maximum of 360 mg daily.
Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.
It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue on with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue on with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.
Store this medication at room temperature, protect it from light and moisture, and keep it out of the sight and reach of children.
Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.
What form(s) does this medication come in?
ratio-Diltiazem CD is no longer being manufactured for sale in Canada. For brands that may still be available, search under diltiazem. This article is being kept available for reference purposes only. If you are using this medication, speak with your doctor or pharmacist for information about your treatment options.
Who should NOT take this medication?
Do not take diltiazem if you:
- are allergic to diltiazem or any ingredients of the medication
- are or may become pregnant
- have certain types of heart rhythm problems in the absence of a pacemaker
- have very low blood pressure
- have weakened pumping action of the heart (called left ventricular failure)