Antiplatelets — patient guide

This page covers all the medicines in the antiplatelet family — aspirin, clopidogrel, ticagrelor, prasugrel, dipyridamole, and combinations like Asasantin SR. If you are on any of these, this is your page.

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Find your medicine

Generic name	Common brand names	Strengths	How often
Aspirin (low-dose)	Cartia, Astrix, Cardiprin, Solprin, DBL Aspirin, generics	75 / 100 / 150 mg	Once daily
Clopidogrel	Plavix, Iscover, generics	75 mg	Once daily
Ticagrelor	Brilinta	60 / 90 mg	Twice daily
Prasugrel	Effient	5 / 10 mg	Once daily
Dipyridamole	Persantin, Persantin SR	200 mg	Twice daily
Dipyridamole + aspirin	Asasantin SR	200 / 25 mg	Twice daily

Brand-swap note: generic aspirin, clopidogrel, and the rest are bioequivalent — they work the same as the branded versions. If the pharmacist offers a cheaper generic, that is fine. The exception worth knowing: brand-name Plavix and generic clopidogrel sometimes look very different in colour or markings, but the medicine inside is the same.

Closely related family — anticoagulants (warfarin, apixaban, rivaroxaban, dabigatran). These also reduce clotting but work through a different mechanism. Some people are on an antiplatelet and an anticoagulant at the same time for a defined period — that is called triple therapy and carries a much higher bleeding risk. See the anticoagulants page for that conversation.

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What it treats

Antiplatelets are used to prevent blood clots forming inside arteries — the kind of clot that causes a heart attack or an ischaemic stroke.

Your reason will usually be one of these:

• After a heart attack — long-term aspirin, often with a second antiplatelet for the first 12 months.
• After a coronary stent — dual antiplatelet therapy (DAPT) for a defined period, then aspirin alone.
• After a stroke or TIA — aspirin, clopidogrel, or aspirin-dipyridamole long-term.
• Peripheral arterial disease — usually aspirin or clopidogrel.
• Acute coronary syndrome — loading dose plus dual therapy at the time of the event.
• Selected high-cardiovascular-risk adults aged 40-59 who have not had an event — only as a shared decision after weighing the bleeding risk. See the primary-prevention block below.

The next section is the most important one to read carefully if no one has explained the difference between primary and secondary prevention.

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Primary prevention vs secondary prevention — the most important distinction

This is the part of antiplatelet care that gets misunderstood more than any other.

• Secondary prevention means you have already had an event — a heart attack, a stroke, a TIA, a stent, or you have peripheral arterial disease. The clot has already happened once. Aspirin (often with a second antiplatelet for a defined period) reduces the chance of it happening again. Here the evidence is strong, the benefit clearly outweighs the bleeding harm, and aspirin is standard care.

• Primary prevention means you have never had any of those events. You are taking aspirin “just in case.” For most people, the evidence here has shifted in the past few years.

Three large trials between 2018 and 2019 changed how Australian GPs and the USPSTF now think about daily aspirin in healthy adults:

• ASPREE — adults aged 70 and over (65 and over for Indigenous Australians and African Americans). Daily 100 mg aspirin did not reduce death, heart disease or disability. It did increase major bleeding, including intracranial haemorrhage. There was a small unexplained increase in all-cause mortality.

• ASCEND — adults with diabetes and no known cardiovascular disease. Daily 100 mg aspirin reduced serious vascular events by 12% but increased major bleeding by 29%. The two effects roughly cancelled out.

• ARRIVE — adults at moderate cardiovascular risk. No reduction in heart attack or stroke, but more bleeding.

What this means in practice:

• If you are over 60 and have never had a cardiac event, starting aspirin is generally not recommended. If you are already on it for primary prevention, talk to your GP about whether to continue.
• If you are 40-59 with a 10-year cardiovascular risk above 10% and a low bleeding risk, a daily low-dose aspirin may still be reasonable — but only as an explicit shared decision after weighing your individual risks. It is not a default.
• If you have already had a heart attack, stroke, TIA, stent, or PAD, none of the above applies to you — your situation is secondary prevention and aspirin remains standard.

This is the single most common reason patients ask me to review their tablets. If you are not sure which bucket you are in, ask.

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The basics

1. Take it at the same time every day. Most antiplatelets are once daily; ticagrelor, dipyridamole and Asasantin SR are twice daily. Miss a dose? Take the next one — do not double up.
2. Go to ED if you have black or tarry stools, vomit that looks like coffee grounds, a prolonged nosebleed that will not stop after 20 minutes of pressure, a sudden very severe headache (worst of your life), or new weakness, numbness, or speech change.
3. Do not stop on your own — especially within 12 months of a stent. Stent thrombosis is a heart attack, and stopping your antiplatelet too early is the single biggest preventable cause.

Everything else — bleeding, dual therapy, periop rules, integrative angle — is below.

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Bleeding — what to watch for

Antiplatelets work by making platelets less sticky. The flip side is bleeding. Across the class, the major bleeding rate on single therapy in secondary-prevention patients is roughly 1-2% per year. Intracranial haemorrhage is the most feared. It runs at 0.1-0.3% per year. The most common bleeding site is the gut.

Go to ED for any of these:

• Black or tarry stools, or fresh red blood from the bowel
• Vomit that looks like coffee grounds, or contains bright red blood
• A nosebleed that does not stop after 20 minutes of firm pressure
• A sudden severe headache — worst of your life — with or without neck stiffness or vomiting
• New weakness, numbness, drooping of the face, slurred speech, or loss of vision

Same-day GP or ED:

• A noticeable bruise without a memory of injury. Especially if you are bruising in unusual places.
• Unexplained tiredness, breathlessness on exertion, or paleness. These can be signs of slow gut blood loss causing anaemia.
• Heavy or prolonged menstrual bleeding that is new for you

Reduce avoidable bleeding risk by:

• Telling every prescriber and every pharmacist that you are on an antiplatelet
• Avoiding regular ibuprofen, diclofenac, naproxen, and celecoxib. Paracetamol is fine.
• Treating Helicobacter pylori if you have a history of ulcer disease. Test-and-treat is supported by eTG.
• Moderating alcohol — see the integrative section

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Tap any section below to expand the detail.

How do antiplatelets work?

Platelets are small blood cells that gather together at the site of an injury to form a clot. That is essential when you cut yourself. It is dangerous when it happens inside a narrowed coronary artery or on the surface of a stent — the clot blocks the vessel and causes a heart attack or stroke.

Each antiplatelet medicine makes platelets less sticky through a different door:

• Aspirin blocks an enzyme (cyclooxygenase-1) for the full life of the platelet, which is 7-10 days. One low daily dose is enough.
• Clopidogrel, ticagrelor and prasugrel block a receptor on the platelet called P2Y12. Clopidogrel and prasugrel are prodrugs — your liver switches them on. Ticagrelor is direct-acting.
• Dipyridamole works through two other mechanisms — it inhibits an enzyme called phosphodiesterase and blocks the reuptake of adenosine. It also relaxes blood vessels.

The combinations (DAPT — dual antiplatelet therapy) hit two different pathways at once. That is more effective at preventing clot, and it is more likely to cause bleeding.

Dual antiplatelet therapy (DAPT) — why two at once, and for how long?

After a coronary stent or a heart attack, you are usually started on two antiplatelets at once — aspirin plus a P2Y12 inhibitor (clopidogrel, ticagrelor, or prasugrel). The combination is called DAPT.

Why two? Because a brand-new stent surface is vulnerable to clot formation until your own endothelial cells grow over it. Two antiplatelets working through different pathways protect that window.

Standard durations:

• After a heart attack (ACS): aspirin + a P2Y12 inhibitor for 12 months, then aspirin alone long-term. The P2Y12 partner is usually ticagrelor or prasugrel, with clopidogrel as the alternative.
• After an elective stent for stable angina with a modern drug-eluting stent: aspirin + clopidogrel for 6 months, then aspirin alone long-term.
• After a minor stroke or high-risk TIA: short-course aspirin + clopidogrel for 21-90 days based on CHANCE and POINT, then single antiplatelet long-term.

Newer evidence is shifting this picture. MASTER DAPT and TWILIGHT show that for people with high bleeding risk, dropping one of the two antiplatelets earlier (sometimes after 1-3 months) is safer overall without increasing clot risk. Your cardiologist is making this call based on your individual bleeding risk profile, the type of stent, and the procedure complexity.

The non-negotiable rule: do not stop either antiplatelet during the DAPT period without the cardiologist signing off. Stent thrombosis is a heart attack, and stopping early is the single biggest avoidable cause.

Side effects in detail

Common (usually mild)

• Bruising — easier and more visible than before starting. Usually cosmetic.
• Dyspepsia (heartburn, indigestion) — most common with aspirin, less with clopidogrel. Enteric coating helps but does not eliminate it.
• Headache — common with dipyridamole and Asasantin SR in the first 1-2 weeks. Usually settles. Paracetamol is the safe analgesic.
• Dyspnoea — affects around 15% of people on ticagrelor. Adenosine-mediated. Usually mild and self-limiting, but can be disabling and warrants a discussion with the prescriber.
• Minor bleeding — gums when brushing, prolonged bleeding from small cuts. Annoying but not dangerous.

Less common

• Higher bruise rate or petechiae (tiny red dots in the skin) — mention to your GP.
• Iron-deficiency anaemia from slow gut blood loss — picked up on annual blood tests. New tiredness or breathlessness is the symptom to act on.
• Bradyarrhythmia with ticagrelor — pauses or slow heart rate, particularly in people with pre-existing sinus node disease. Report dizziness, palpitations, or fainting.

Rare but serious — go to ED

• Major GI bleed — black or tarry stools, fresh red blood, coffee-ground vomit.
• Intracranial haemorrhage — sudden severe headache, new neurological signs.
• Severe nosebleed that will not stop with 20 minutes of pressure.
• Anaphylaxis or angioedema — sudden swelling of lips, tongue, throat, or full-body urticaria.
• Aspirin-exacerbated bronchospasm in people with asthma + nasal polyps (Samter triad).

Drugs, food, and alcohol

Tell your GP or pharmacist before combining your antiplatelet with:

• Anti-inflammatories (ibuprofen / Nurofen, diclofenac / Voltaren, naproxen, celecoxib). All add to gut bleeding risk. Ibuprofen also competes with aspirin for the same platelet binding site — separate the doses by at least 2 hours (aspirin first). Paracetamol is preferred.

• Other antiplatelets — combining two antiplatelets is dual therapy and is a deliberate, time-limited cardiology decision. Do not stack them on your own.

• Oral anticoagulants (warfarin, apixaban / Eliquis, rivaroxaban / Xarelto, dabigatran / Pradaxa, edoxaban). Adding an anticoagulant to your antiplatelet substantially increases bleeding risk. The combination is reserved for specific situations (such as atrial fibrillation plus a recent stent) and is usually time-limited under specialist oversight.

• SSRIs and SNRIs (sertraline, escitalopram, venlafaxine, duloxetine and similar). Modest additive gut bleeding risk. Often manageable, sometimes a reason to add a PPI.

• Systemic corticosteroids (prednisolone, dexamethasone). Adds gut ulceration and bleeding risk — a PPI is usually appropriate during co-prescription.

• Omeprazole or esomeprazole + clopidogrel. Both PPIs block the CYP2C19 enzyme that switches clopidogrel on. If you need a PPI, ask for pantoprazole (Somac) or rabeprazole (Pariet) — neither interferes with clopidogrel.

• Macrolide antibiotics with ticagrelor — clarithromycin and erythromycin raise ticagrelor levels (CYP3A4 inhibition). Azithromycin is lower-risk.

• Azole antifungals with ticagrelor (itraconazole, ketoconazole) — avoid the combination or pause ticagrelor for a short antifungal course on specialist advice.

• St John’s wort, carbamazepine, phenytoin, rifampicin with ticagrelor — reduce ticagrelor effect. Avoid.

• Lithium with aspirin — aspirin can raise lithium levels; monitor more closely.

Food. No specific food restrictions. The supplement and herbal interactions worth knowing are in the integrative section below.

Alcohol. Light to moderate amounts are usually okay. Heavy drinking adds substantially to gut bleeding risk and can mask early warning signs (tiredness, light-headedness, dark stools). The AU guideline is no more than 10 standard drinks a week and no more than 4 on any one day. On dual therapy, stay well below that ceiling.

Generic substitution. Generics are bioequivalent. Take whichever the pharmacist offers — the price difference can be substantial.

PPI cover — when and which one

A proton-pump inhibitor reduces the chance of a serious gut bleed in people on antiplatelets. It is not needed for everyone, but it is recommended if you have any of these:

• Age 75 or over
• Prior peptic ulcer or GI bleed
• Currently on an oral anticoagulant
• Currently on a regular NSAID or systemic steroid
• Helicobacter pylori positive

The PPI choice matters if you are on clopidogrel. Omeprazole (Losec) and esomeprazole (Nexium) block the CYP2C19 enzyme that switches clopidogrel on. The clinical signal is real but modest. The simple fix is to use pantoprazole (Somac) or rabeprazole (Pariet) instead — neither interferes with clopidogrel activation. There is no such interaction with aspirin, ticagrelor or prasugrel.

See the PPIs page for the longer conversation about gut-acid medicines.

Periop hold — what to do before surgery or dental work

This is one of the most common questions. The answer depends on the drug and the procedure.

Aspirin (low-dose):

• For most dental work, simple skin procedures, and most eye procedures — continue. The bleeding risk is usually less than the clotting risk if you stop.
• For major surgery — the surgical team decides. Usually continued; sometimes held for 7 days.

Clopidogrel and ticagrelor:

• For most major surgery — held for 5-7 days pre-op.
• For dental extractions, simple skin procedures, and many eye procedures — often continued with local haemostatic measures.

Prasugrel:

• Held for 7 days pre-op for major surgery.

The critical exception — recent stent. If you have had a stent in the past 6 months (especially a drug-eluting stent), do not stop your antiplatelet without your cardiologist’s explicit sign-off. Stopping early is the leading cause of stent thrombosis, which is a heart attack. The surgical team needs to talk to the cardiology team, not just to you.

If your surgeon or dentist tells you to stop your tablet and the timing feels rushed, message us and we will check the plan.

Pregnancy and breastfeeding

Low-dose aspirin (100-150 mg) is safe in the second and third trimesters and is in fact indicated for women at high risk of pre-eclampsia. RANZCOG and the ASPRE trial support starting low-dose aspirin from 12-16 weeks gestation in women with prior pre-eclampsia, chronic hypertension, pre-existing diabetes, autoimmune disease, multifetal pregnancy, or a high-risk first-trimester screen. This is a standard part of AU antenatal care.

High-dose aspirin is avoided in pregnancy.

Clopidogrel, ticagrelor, prasugrel — limited human pregnancy data. Generally avoided unless the cardiac indication is too important to drop. Decisions are made jointly by cardiology, obstetrics and the patient.

Breastfeeding:

• Low-dose aspirin — low transfer, generally compatible.
• Clopidogrel, ticagrelor, prasugrel — limited data, generally avoided. Discuss with the prescriber and lactation specialist.

If you are planning a pregnancy and you are on any of these, talk to your GP before you start trying.

Cost

From 1 January 2026, the PBS co-payment is:

• General patient: up to $25.00 per script
• Concession card holder: up to $7.70 per script

Aspirin (low-dose) is also available over the counter at most pharmacies for around $5-10 for a 60-90 day supply — cheaper than the PBS co-payment for general patients.

Clopidogrel, ticagrelor, prasugrel, dipyridamole are all PBS-listed for the cardiac indications. Clopidogrel is generally Streamlined Authority; ticagrelor and prasugrel are Authority Required (your GP or cardiologist arranges this). Generics are usually substantially cheaper than brand names.

Confirm exact pricing with your pharmacist — they can show you the lowest-cost option for your script.

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The integrative view

Most of the patients I see on antiplatelets want to know what they can do alongside the tablet — both to support their cardiovascular health and to avoid accidentally adding to the bleeding risk. This section is the longer version of that conversation.

Two principles. First: the antiplatelet is doing structural work — making clot formation less likely on a vessel surface that has already shown it can form one. Lifestyle and supplements do not replace it. Second: every supplement that has an effect on platelets can stack with the tablet. The question is whether the stack is wanted or not.

Strong evidence — these matter most

These are the interventions where the cardiovascular data is solid enough that I would discuss them with every patient on an antiplatelet.

• Mediterranean-style eating pattern. Reduces recurrent cardiovascular events. Vegetables, legumes, whole grains, oily fish, olive oil, nuts. Lower added sugar and processed meat.
• Aerobic exercise. 150 minutes per week of brisk walking, cycling, swimming, or equivalent. Independent reduction in recurrent events.
• Resistance training. 2-3 sessions per week. Adds metabolic and cardiac benefit on top of aerobic.
• Smoking cessation. This is the single highest-leverage intervention for anyone with cardiovascular disease.
• Blood pressure control. Talk to your GP about home BP monitoring and your target.
• LDL cholesterol control. Usually with a statin (see the statins page).
• Treating Helicobacter pylori if you are positive — reduces ulcer and gut bleeding risk on long-term antiplatelet therapy. AU eTG and Maastricht VI guidance both support test-and-treat in this group.
• Annual full blood count and iron studies on long-term antiplatelet therapy — catches slow gut blood loss before it becomes a problem.

Moderate evidence — likely helpful

• Stress reduction practices — slow breathing at about 6 breaths per minute, meditation, yoga. Modest BP and autonomic benefit over months of practice.
• Sleep apnoea diagnosis and treatment if snoring + daytime tiredness + observed pauses. Treatment reduces cardiovascular event risk.
• Magnesium-rich foods (leafy greens, nuts, seeds, legumes, dark chocolate). Modest BP benefit, particularly if intake has been low.

Where the integrative + antiplatelet conversation gets specific — supplements that stack on bleeding

These are the supplements with a real antiplatelet effect of their own. Each one stacks with your tablet. None of them are reasons to stop a supplement you find genuinely useful — they are reasons to tell me and your pharmacist so we can think it through together.

• High-dose omega-3 / fish oil over 3 g EPA+DHA daily — measurable antiplatelet effect via thromboxane modulation. Dietary fish and standard-dose supplements (1-2 g) are not the issue.
• Turmeric / curcumin concentrated extracts at 500-1000 mg twice daily — additive antiplatelet effect. Culinary turmeric in curry is fine.
• Ginkgo biloba — well-documented antiplatelet effect and the most cited herb-drug bleeding interaction. Case reports of spontaneous bleeding with antiplatelets and anticoagulants. Avoid the combination.
• Concentrated aged-garlic extract at supplement doses — additive antiplatelet effect. Culinary garlic is fine.
• High-dose ginger supplements — additive antiplatelet effect. Culinary ginger is fine.
• High-dose vitamin E above 400 IU daily — modest additive antiplatelet effect.

Specific to being on an antiplatelet

• Alcohol. Adds to gut bleeding risk and can mask early warning signs. AU guideline ceiling is 10 standard drinks per week and 4 in any single day. On dual therapy for the first few months, sitting well below that is sensible.
• Iron, B12, folate. Long-term antiplatelets can produce slow occult gut blood loss and a gradually developing iron-deficiency anaemia. A yearly full blood count plus iron studies, B12, and folate is reasonable. New tiredness, breathlessness on exertion, or paleness is worth investigating sooner.
• Cranberry juice. Has been flagged historically as a warfarin interaction. The antiplatelet signal is weaker, but worth noting if you drink very large daily volumes.

What I do not recommend stopping the tablet for

The antiplatelet is doing structural prevention of a clot on a vessel surface that has already shown it can form one. No supplement, dietary change, or lifestyle intervention replaces that work in someone with secondary-prevention indication. If you are considering coming off your tablet because you feel well, that is the conversation to have with me or your cardiologist — not a unilateral decision.

The exception is primary-prevention aspirin in someone who has never had an event. That is a genuine shared-decision conversation — see the primary-prevention block earlier on this page.

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Cross-reference — other pages

• Anticoagulants — warfarin, apixaban, rivaroxaban, dabigatran. Different mechanism, different bleeding profile. Triple therapy considerations.
• PPIs — when gut-acid cover is appropriate, and the clopidogrel + omeprazole / esomeprazole interaction.
• Statins — combined secondary-prevention context.
• ACE inhibitors and ARBs — combined post-heart-attack medication context.

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Track these between now and your next visit

• Any unusual bleeding or bruising — note when, where, how much, and whether it stopped easily.
• Any new tiredness, breathlessness, or paleness — could be slow gut blood loss.
• Any new medicines (prescription, over-the-counter, or supplements) you have started since your last review.
• Upcoming surgery, dental work, or procedures — let us know early so we can plan any hold.

Bring the list to your review appointment.

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This is general information, not personal medical advice. Every patient is different. Decisions about your antiplatelet — which one, what dose, how long, when to stop, what to combine with — are made with the doctor who prescribed them, usually a cardiologist or your GP working with cardiology. If anything on this page appears to contradict advice from your treating doctor, follow your doctor — they have context about your situation that this page cannot.

Reading this page does not establish a doctor-patient relationship with Dr Hoebing Lo. If you are not a current patient, please discuss your antiplatelet with your own GP, cardiologist, or pharmacist.

About the integrative content. The lifestyle, dietary, and complementary recommendations on this page summarise current published research. Effect sizes are approximations from clinical studies — your individual response will vary, and real-world results are commonly smaller than trial results because day-to-day life differs from study conditions. Supplements and herbal products are not interchangeable with prescribed medication and can interact with it — most relevantly here, several common supplements add to the bleeding risk. Talk to your doctor and pharmacist before starting any new supplement, herbal product, or significant change in diet.

Currency. This page reflects clinical practice as of the last-reviewed date. Antiplatelet practice is evolving — particularly around DAPT duration after stents, and around primary-prevention aspirin in shared-decision contexts. Specific details may date between reviews. Pricing shown is indicative; confirm with your pharmacist.

No commercial relationships. Dr Hoebing Lo has no financial or commercial relationship with the manufacturer of any antiplatelet medicine, supplement, or brand mentioned on this page.

Emergencies. If you have black or tarry stools, vomit that looks like coffee grounds, a prolonged nosebleed that will not stop, a sudden very severe headache, new weakness or speech change, sudden swelling of face, lips, tongue, or throat, difficulty breathing, chest pain, or severe dizziness or fainting, call 000 or go to your nearest emergency department. Do not wait, and do not message us first.