aspirin at a glance
Medicine class
NSAID and antiplatelet medicine.
Main roles
Prevention of clot-related heart or brain events, or relief of pain, fever and inflammation, depending on the formulation.
Age restriction
Do not give aspirin to anyone under 16 unless a doctor specifically advises it.
Bleeding
Aspirin can make bleeding start more easily or take longer to stop.
What is aspirin used for?
Licensed uses depend on the formulation.
Prevention of further clot-related cardiovascular events after a heart attack, or with stable or previous unstable angina.
Prevention of graft blockage after coronary bypass surgery and clot-related complications following coronary angioplasty.
Prevention of further events after a transient ischaemic attack or ischaemic stroke once bleeding within the skull has been excluded.
Treatment of an acute heart attack using an appropriate immediate-release product under medical supervision.
Relief of mild to moderate pain, including headache, migraine, toothache, period pain, neuralgia and sore throat.
Reduction of fever associated with colds or influenza.
Relief of pain and inflammation associated with rheumatic or musculoskeletal conditions.
How does aspirin work?
Aspirin blocks cyclo-oxygenase enzymes, reducing prostaglandins involved in pain, fever and inflammation. In platelets, it irreversibly reduces thromboxane A2 production, making platelets less able to clump and form a clot.
aspirin preparations and strengths
Gastro-resistant tablet
Route: Oral
Strengths: 75 mg
Tablet
Route: Oral
Strengths: 75 mg
Suppository
Route: Rectal
Strengths: 150 mg, 300 mg
How to take aspirin
Follow the product leaflet or prescriber's directions because formulations are not interchangeable.
Swallow standard tablets with water.
Swallow gastro-resistant tablets whole; do not cut, chew or crush them.
Dissolve Disprin fully in water before drinking.
Remove a suppository from its wrapper and insert it into the rectum, rounded end first.
Taking oral aspirin with or after food may reduce indigestion.
aspirin side effects
Common or expected effects
- Indigestion or stomach discomfort.
- Bruising or bleeding more easily, with bleeding taking longer to stop.
Get urgent medical advice
- Stomach or intestinal ulceration or bleeding, possibly causing vomiting blood or black tar-like stools.
- Bronchospasm or an asthma attack, with wheezing or breathlessness.
- Severe allergic reaction, including facial or throat swelling and breathing difficulty.
- Severe skin reactions with blistering or peeling.
- Major internal bleeding or blood-cell disorders.
aspirin in pregnancy
Low-dose aspirin can be used during pregnancy when recommended by a midwife, GP or specialist, including to reduce pre-eclampsia risk or for an established cardiovascular indication. Aspirin for pain relief is not recommended. Later-pregnancy restrictions depend on the product and circumstances, so do not start or stop prescribed aspirin without professional advice.
aspirin while breastfeeding
Low-dose antiplatelet aspirin may be used cautiously after individual assessment, particularly when breastfeeding a healthy, full-term infant. Monitor the baby for poor feeding, irritability, skin reactions, bruising or bleeding, and seek advice for fever or a viral illness. Aspirin for pain relief is generally not recommended; some products, including Disprin, are contraindicated by their licence.
aspirin interactions
Check prescribed, pharmacy and complementary medicines before using aspirin.
Anticoagulants, thrombolytics and other antiplatelet medicines
May increase bleeding and require closer monitoring.
Ibuprofen and other NSAIDs
Increase gastrointestinal and other adverse effects; regular ibuprofen may interfere with aspirin's antiplatelet action.
Common questions about aspirin
Answers are fully visible for fast scanning and source review.
Is low-dose aspirin the same as aspirin for pain?
The active ingredient is the same, but formulation, licensing and intended use differ. Gastro-resistant antiplatelet tablets should not replace a rapid-acting pain-relief product.
Can I take ibuprofen while taking aspirin?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.