Antiplatelets for stroke and transient ischemic attack (TIA)

Examples

Generic Name	Brand Name
acetylsalicylic acid (ASA)	Aspirin, Bufferin
ASA with extended-release dipyridamole	Aggrenox
clopidogrel	Plavix

How It Works

ASA is an antiplatelet medicine that decreases blood clot formation by preventing the smallest blood cells (platelets) from sticking together and forming blood clots.

ASA with extended-release dipyridamole is used to prevent a second ischemic stroke or transient ischemic attack (TIA).

Why It Is Used

ASA is the most commonly used medicine to prevent stroke. ASA:¹

• Reduces the risk of stroke in people who have already had a transient ischemic attack (TIA) or ischemic stroke.
• Can reduce the risk of stroke in those with an irregular heart rhythm (atrial fibrillation) who cannot take warfarin, an anticoagulant.

ASA or other antiplatelet drugs may decrease the risk of stroke in people who cannot have surgery to reopen a blocked carotid artery (carotid endarterectomy).

ASA with extended-release dipyridamole (Aggrenox) is used to reduce the risk of additional strokes or TIAs in people who had a stroke or TIA while taking ASA.

Clopidogrel is most often used for people who have had another transient ischemic attack (TIA) or stroke while taking ASA or for people who cannot take ASA.

Clopidogrel also may be given to people who are allergic to ASA and need a medication to prevent the formation of blood clots.

How Well It Works

ASA reduces the risk of stroke and heart attack or another transient ischemic attack (TIA).¹

ASA reduces the risk of death and dependence due to disability and increases the chance of recovery when it is given within 48 hours of an ischemic stroke that has been confirmed by a computed tomography (CT) scan to rule out hemorrhagic stroke.²

Studies have shown that the combination of ASA and extended-release dipyridamole reduces the risk of stroke by about 30% and is a safe and effective alternative to ASA alone.^{3, 4}

Clopidogrel is a safe and effective alternative to ASA.⁴

It is important for each person to work with his or her doctor to find the best medication.

Side Effects

Side effects of ASA include:

• Skin bruising, especially in older people.
• Irritation of the stomach lining.
• Bleeding from the digestive system.
• Allergic reaction.
• Bleeding (hemorrhage) in the brain (rare) or other internal organs of the body.

Side effects of ASA with extended-release dipyridamole include headache, dizziness, stomach upset, vomiting, and diarrhea.

Common side effects of clopidogrel include:

• Nausea and vomiting.
• Diarrhea.
• Skin rash, itching.

In rare cases, clopidogrel has been associated with a syndrome that resembles a serious bleeding disorder (thrombocytopenic purpura).

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

A large study showed that ASA in doses of 75 to 150 mg daily is as effective as higher doses for long-term treatment.⁵ Higher doses are associated with more side effects, especially bleeding problems.

Safety tips when taking ASA

Follow these safety tips when taking ASA.

• Take the medication at the same time each day.
• Take ASA with food to prevent irritation of the stomach.
• Use buffered or enteric-coated ASA.
• Check with your doctor before using other non-prescription drugs that contain ASA.
• Be on the alert for signs of bleeding, and call your doctor immediately if any signs occur.
• Let your doctor know if you are taking ASA and you are planning to have surgery. You may have to stop the ASA temporarily.

ASA with extended-release dipyridamole is more expensive than ASA alone.

There are no adequate studies on the safety of using dipyridamole during pregnancy.

Experts recommend that short-acting dipyridamole alone not be used by people who have chronic stable angina (an indicator of coronary artery disease) because dipyridamole may reduce blood flow to portions of the heart (ischemia) during exercise.⁶ Extended-release formulations, such as Aggrenox, do not appear to have this risk and may be safe for people with angina. Talk to your doctor if you are considering taking a medicine that contains dipyridamole.

Clopidogrel is commonly used in people who have had a stroke and heart disease. Clopidogrel may be preferred as an alternative to ASA.⁴

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.

Author:	Douglas Dana Robin Parks, MS	Last Updated: May 14, 2007
Medical Review:	Anne C. Poinier, MD - Internal Medicine Andrew Swan, MD, CCFP, FCFP - Family Medicine Richard D. Zorowitz, MD - Physical Medicine and Rehabilitation
© 1995-2008 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.