How does this medication work? What will it do for me?

This combination product contains 2 medications: ASA (acetylsalicylic acid) and dipyridamole. It belongs to the family of medications called antiplatelet agents. This medication is used to reduce the risk of stroke in people who have had transient ischemic attacks (TIAs) and in those who have had an ischemic stroke due to thrombosis (blockage of a blood vessel in the brain).

Strokes result from the brain getting less oxygen from the blood than it needs to function. When the reduced blood flow to the brain is caused by blockage of a blood vessel by a blood clot, it is called an ischemic stroke. The blood clot that eventually ends up in the brain may have travelled from almost any part of the body.

Both ASA and dipyridamole work to reduce prevent platelets from sticking together. Platelets are components of the blood that tend to clump together under certain circumstances and help to start the blood clotting process. ASA - dipyridamole extended release prevents the formation of blood clots by reducing the action of platelets.

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.

What form(s) does this medication come in?

Aggrenox is no longer being manufactured for sale in Canada. For brands that may still be available, search under ASA - dipyridamole extended release. 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.

How should I use this medication?

The usual dose of ASA - dipyridamole extended release is 1 capsule 2 times daily, in the morning and evening. The capsules should be swallowed whole without chewing. ASA - dipyridamole can be taken with or without food.

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 different dose than 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 with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue 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 moisture, and keep it out of the 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.

Who should NOT take this medication?

Do not take this medication if you:

  • are allergic to ASA, dipyridamole, or any ingredients of the medication
  • are allergic to nonsteroidal anti-inflammatory drugs (NSAIDs)
  • are intolerant to fructose or galactose
  • have asthma, rhinitis (runny nose), or nasal polyps
  • have bleeding in the digestive tract or stomach ulcers
  • are in the last 3 months of pregnancy

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • abdominal pain
  • diarrhea
  • dizziness
  • headache
  • heartburn
  • hot flashes
  • indigestion
  • muscle pain
  • nausea
  • vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • migraine-like headache
  • rapid heartbeat
  • signs of anemia, e.g.:
    • breathlessness
    • continuous lack of energy and tiredness
    • fast heartbeat
  • signs of bleeding (e.g., nosebleeds or bleeding around the gums when eating)
  • signs of low blood pressure (e.g., headache, dizziness, fainting, fatigue)
  • signs of worsening heart problems:
    • chest pain
    • weakness
    • breathlessness
  • tingling or numbness in extremities of the body

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • signs of a serious allergic reaction, e.g.:
    • difficulty breathing
    • hives
    • swelling of face or throat
  • signs of excessive bleeding, e.g.:
    • bleeding from rectum
    • bloody urine
    • dark stools
    • easy bruising
    • persistent abdominal pain
    • vomiting
  • signs of stomach ulcers, e.g.:
    • dark stools
    • persistent abdominal pain
    • vomiting blood
  • signs of stroke (e.g., sudden or severe headache; sudden loss of coordination; vision changes; sudden slurring of speech; or unexplained weakness, numbness, or pain in arm or leg)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.


June 8, 2021

Health Canada has issued new information concerning the use of non-steroidal anti-inflammatory drugs (NSAIDs). To read the full Health Canada Advisory, visit Health Canada's web site at

Alcohol: The risk of stomach bleeding with this medication increases if you have 3 or more alcoholic drinks per day.

Allergy and breathing problems: People who have asthma, long-term breathing problems, or allergic conditions such as hay fever or nasal polyps are more likely to experience difficulty breathing and allergic reactions caused by ASA. If you have a history of allergic reactions to other substances, or respiratory illness, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Bleeding problems: ASA - dipyridamole increases the risk of bleeding. Using other medications (e.g., antiplatelets, selective serotonin reuptake inhibitors) may further increase the risk of bleeding. Stop taking the medication and seek immediate medical attention if you experience signs of serious or excessive bleeding, e.g.:

  • bleeding from the rectum
  • bloody urine
  • dark stools
  • easy bruising
  • persistent abdominal pain
  • vomiting

Drowsiness/reduced alertness: ASA - dipyridamole extended release may cause drowsiness or dizziness, affecting your ability to drive or operate machinery. Avoid these and other hazardous tasks until you have determined how this medication affects you.

Heart problems: Dipyridamole causes the muscles around the blood vessels to relax, possibly reducing blood pressure. Certain heart problems may be made worse by this effect. If you take medication to reduce blood pressure, have chest pain (angina), or have recently had a heart attack, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Kidney function: If you have reduced kidney function or kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: If you have reduced liver function or liver disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.  This medication should not be used during the last 3 months of pregnancy.

Breast-feeding: Both ASA and dipyridamole pass into breast milk. If you are a breast-feeding mother and are taking ASA - dipyridamole, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

What other drugs could interact with this medication?

There may be an interaction between ASA - dipyridamole extended release and any of the following:

  • acetylcholinesterase inhibitors (e.g., donepezil, galantamine, rivastigmine)
  • acetylsalicylic acid (ASA)
  • acetazolamide
  • alcohol
  • alendronate
  • anagrelide
  • angiotensin converting enzyme inhibitors (ACEIs; e.g., captopril, enalapril, ramipril)
  • alendronate
  • apixaban
  • beta blockers (e.g., atenolol, metoprolol, propranolol)
  • bromocriptine
  • calcium channel blockers (e.g., diltiazem, verapamil)
  • clomipramine
  • clopidogrel
  • corticosteroids (e.g., prednisone, prednisolone)
  • cyclosporine
  • dabigatran
  • deoxycholic acid
  • diabetes medications (e.g., glyburide, insulin, metformin, rosiglitazone)
  • dipyridamole
  • diuretics (e.g., bumetanide, ethacrynic acid, furosemide)
  • edoxaban
  • guanfacine
  • heparin
  • herbal medications (e.g., garlic, ginger, gingko, ginseng)
  • hyaluronidase
  • hydroxychloroquine
  • icosapent ethyl
  • low molecular weight heparins (e.g., dalteparin, enoxaparin, tinzaparin)
  • methazolamide
  • methotrexate
  • mifepristone
  • multivitamin and mineral supplements
  • nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., ibuprofen, ketorolac, naproxen)
  • obinutuzumab
  • omega-3 fatty acids
  • pentoxifylline
  • certain protein kinase inhibitors (e.g., acalabrutinib, dasatinib, sunitinib)
  • prasugrel
  • quinolone antibiotics (e.g., ciprofloxacin, norfloxacin, ofloxacin)
  • quinine
  • riociguat
  • rivaroxaban
  • seizure medications (e.g., divalproex, topiramate, valproic acid)
  • selective serotonin reuptake inhibitors (SSRIs; e.g., fluoxetine, paroxetine, sertraline, etc.)
  • serotonin-norepinephrine reuptake inhibitors (SNRIs; desvenlafaxine, duloxetine, venlafaxine)
  • spironolactone
  • sodium phosphates
  • somatostatin analogues (e.g., lanreotide, octreotide, pasireotide)
  • tetracycline antibiotics (e.g., doxycycline, minocycline, tetracycline)
  • ticagrelor
  • tipranavir
  • tramadol
  • warfarin
  • vaccines
  • vitamin E

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

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