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Details for: DILTIAZEM - CD


DIN DIN name Active Ingredient(s) Strength Dosage Form Route of Administration

As of 2018-03-31 side effects have not been reported for this drug product name.

All side effects reported are for domestic, post-market data from 1965-01-01 to 2018-03-31 only. This database is updated quarterly to reflect new information.

Search for side effects reported with other drug products with the same Active Ingredient(s).
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Consumer Information

This information was provided by the drug’s manufacturer when this drug product was approved for sale in Canada. It is designed for consumers and care givers. It is a summary of information about the drug and will not tell you everything about the drug. Contact your doctor or pharmacist if you have any questions about the drug.

What the medication is used for

Diltiazem-CD is used for:

  • the management of effort associated angina (chest pain)
  • the treatment of mild to moderate high blood pressure.

Diltiazem-CD should normally be used in those patients in whom treatment with other blood pressure reduction medications has been ineffective, or have been associated with unacceptable side effects.

What it does

Diltiazem-CD belongs to the group of drugs called “calcium channel blockers” or “calcium antagonists”. Diltiazem-CD relaxes the arteries, thereby lowering blood pressure.

Diltiazem-CD reduces the amount of oxygen that your heart muscle needs. This helps control chest pain.

When it should not be used

Do not use Diltiazem-CD if:

  • You are pregnant or plan to become pregnant.
  • You are breastfeeding.
  • You have a known allergy to diltiazem or to any of the nonmedicinal ingredients.
  • You have very low blood pressure (< 90 mmHg systolic).
  • You have heart rhythm disorders in the absence of a pacemaker.
  • You have severe heart failure with fluid in the lungs.
  • You are taking a medicine called dantrolene used for severe muscle spasms or severe fever.
  • You are using ivabradine
What the medicinal ingredient is

Diltiazem Hydrochloride

What the non-medicinal ingredients are

Acetyl tributyl citrate, ethylcellulose, magnesium stearate, methylacrylic acid copolymer Type B, polysorbate, sugar spheres and talc. The gelatin capsules contain: black iron oxide (300 mg only), FD&C blue #1, gelatin and titanium dioxide.

What dosage form it comes in

Capsules: 120 mg, 180 mg, 240 mg, and 300 mg.

Warnings and precautions

BEFORE you use Diltiazem-CD talk to your doctor or pharmacist if:

  • You have very low blood pressure.
  • You have ever had a bad or unusual reaction to any drug containing diltiazem in the past.
  • You have heart, liver, or kidney disease.
  • You have high blood sugar or diabetes.
  • You are 65 years or older.
Interactions with this medication

As with most medicines, interactions with other drugs are possible. Tell your doctor, nurse, or pharmacist about all the medicines you take, including drugs prescribed by other doctors, vitamins, minerals, natural supplements, or alternative medicines.

Additional monitoring of your dose or condition may be needed if you are taking other drugs.

The following may interact with Diltiazem-CD:

  • Antifungal medications with a name ending in azole;
  • Medications used to control the immune system such as cyclosporine;
  • Certain antibiotics should not be taken with Diltiazem-CD such as erythromycin, rifampin. Check with your pharmacist if not sure;
  • Sleeping pills such as benzodiazepines (midazolam, triazolam);
  • Other blood pressure medications: alpha antagonists, beta-blockers;
  • Heart medications: Amiodarone, digoxin, digitalis, flecainide, nifedipine, propafenone, quinidine, verapamil;
  • Anaesthetics;
  • Lithium and imipramine used for some types of mental illness;
  • Drugs that dilate the blood vessels: short and long acting nitrates; Medications used to control seizures: carbamazepine, phenobarbital, phenytoin;
  • Warfarin used as anticoagulant;
  • Cholesterol lowering medications: statins;
  • Theophylline used for breathing problems;
  • Terfenadine or ranitidine used for allergies;
  • Medications used to control stomach ulcers such as cimetidine will increase the effects of Diltiazem-CD;
  • Multivitamins with minerals (calcium-containing products);
  • Drugs to treat inflammation: corticosteroids, methylprednisolone;
  • Dantrolene used for severe muscle spasms or severe fever.
  • Acetylsalicylic acid (Aspirin)
  • X-Ray contrast agents.

Alcohol may cause low blood pressure and dizziness when you go from lying or sitting to standing up. This can especially occur after the first dose and when the dose is increased. Tell your doctor if you experience dizziness, light-headedness, fainting, decreased blood pressure or increased heart rate.

Grapefruit juice when consumed too often while taking Diltiazem-CD may cause headache, irregular heartbeat, edema (swelling), unexplained weight gain, and chest pain. Tell your doctor if this happens to you. Your doctor may recommend that grapefruit juice be avoided if this happens to you.

Proper use of this medication
  • Do not miss doses or take extra doses, unless your doctor tells you. If you are not clear about the directions, ask your doctor or pharmacist.

Take Diltiazem-CD exactly as your doctor tells you.

  • Diltiazem-CD is taken once a day
  • Dosage should be individualised.

Swallow capsules whole. DO NOT chew or crush Diltiazem-CD capsules.

Usual Adult Dose


    Starting dose: 120 mg to 180 mg once a day.
    Dose may be slowly (over 7 to 14 days) increased up to 360 mg a day. Always follow your doctor’s instructions.
High blood pressure

    Usual starting doses: 180 to 240 mg once a day.
    120 mg a day may be used in some patients.
    Maximum dose: 360 mg a day.


In case of drug overdose, contact a health care practitioner, hospital emergency department or regional Poison Control Centre immediately, even if there are no symptoms.

Missed Dose

a dose of this medication has been missed, it should be taken as soon as possible. However, if it is almost time for the next dose, skip the missed dose and go back to the regular dosing schedule.

Side effects and what to do about them

Side effects may include:

  • Headache, dizziness, malaise;
  • Nausea (feeling like vomiting);
  • Flushing (facial redness) or feeling unusually warm;
  • Unusual tiredness and weakness;
  • Upset stomach.

Diltiazem-CD can cause abnormal blood results. Your doctor will decide when to perform blood tests and will interpret the results.

Serious side effects, how often they happen and what to do about them
Symptom / effect Talk with your doctor, nurse, or pharmacist Only if severe Talk with your doctor, nurse, or pharmacist In all cases Stop taking drug and seek immediate medical help
Low Blood Pressure: dizziness, fainting, light-headedness
May occur when you go from lying or sitting to standing up.
Fast, slow, or irregular heartbeat    
Peripheral edema: swelling of the ankles    
Respiratory tract infection: pharyngitis, rhinitis    
Allergic Reaction: rash, hives, swelling of the face, lips, tongue or throat, difficulty swallowing or breathing    
Depression: low mood, lack of interest in usual activities, change in sleep and appetite.    
Heart block:
A disease in the electrical system of the heart causing lightheadedness, fainting and irregular heartbeat.
Heart Attack: shortness of breath, chest pain    
Angina: Chest pain    
Heart Failure: shortness of breath, leg swelling, and exercise intolerance.    
Eye Problems: decreased vision, irritation, sore red eyes    
Increased blood sugar: frequent urination, thirst, and hunger    
Liver Disorder: yellowing of the skin or eyes, dark urine, abdominal pain, nausea, vomiting, loss of appetite    
Serious Skin Reactions (Stevens-Johnson Syndrome, Toxic Epidermal Necrolysis, hypersensitivity Syndrome): any combination of itchy skin rash, redness, blistering and peeling of the skin and /or of the lips, eyes, mouth, nasal passages or genitals, accompanied by fever, chills, headache, cough, body aches or joint pain, yellowing of the skin or eyes, dark urine.    

This is not a complete list of side effects. For any unexpected effects while taking Diltiazem-CD, contact your doctor or pharmacist.

How to store

Store Diltiazem-CD capsules in tight containers between 15 and 30°C. Protect from light. Keep out of sight and reach of children.

Reporting side effects

You can report any suspected adverse reactions associated with the use of health products to the Canada Vigilance Program by one of the following 3 ways:

  • Report online at
  • Call toll-free at 1-866-234-2345
  • Complete a Canada Vigilance Reporting Form and:
    • Fax toll-free to 1-866-678-6789, or
    • Mail to: Canada Vigilance Program
      Health Canada
      Postal Locator 0701E
      Ottawa, Ontario
      K1A 0K9

    Postage paid labels, Canada Vigilance Reporting Form and the adverse reaction reporting guidelines are available on the MedEffect™ Canada Web site at

NOTE: Should you require information related to the management of side effects, contact your health professional. The Canada Vigilance Program does not provide medical advice.

More information

This document plus the full product monograph, prepared for health professionals can be found by contacting Pro Doc Ltée at 1-800-361-8559, or

This leaflet was prepared by
Pro Doc Ltée, Laval, Québec, H7L 3W9

Last revised: March 12, 2018

Date modified: