Aspirin is a common medicine that has a number of uses, from relieving pain to reducing the risk of serious problems such as heart attacks and strokes. It comes in many forms, including pills, tablets that are dissolved in water, powders and oral gels.
Some types can be bought over the counter
from pharmacies, while others are only available on prescription.
Uses for aspirin
At high doses – usually 300mg – aspirin can relieve pain, reduce a high temperature (fever) and reduce swelling. It is often used for short-term relief from:
- headaches and migraines
- toothache
- period pains
- general
aches and pains
- colds and flu.
Long-term treatment with low doses of
aspirin – usually 75mg – has an antiplatelet effect, which means
it makes the blood less sticky and can stop blood clots developing. A doctor may recommend this if you have or have
had:
- a heart attack or angina
- a stroke or transient ischemic attack (TIA)
- peripheral arterial disease (PAD)
- coronary artery bypass surgery or another operation on your heart or blood vessels.
Photo of Aspirin tablets by Bayer.
Aspirin may also be prescribed for children after
heart surgery or to treat Kawasaki disease. But it should not be given
to anyone under 16 years old without medical supervision.
Who can and cannot take aspirin
Most people can take aspirin safely. But you should get advice from a pharmacist or doctor before taking it if you:
- have
had an allergic reaction to aspirin
or non-steroidal anti-inflammatory drugs (NSAIDs),
such as ibuprofen, in the past
- have asthma
- have
had stomach ulcers in the past
- have
severe liver or kidney problems
- have haemophilia or
another bleeding disorder
- have uncontrolled high blood pressure
- are
looking for medication for a child under 16 – medication containing
aspirin shouldn't be given to children under 16
- are
over 65 years of age
- are
pregnant, breastfeeding or trying to get pregnant
- are
taking other medications.
You may still be able to take aspirin in these
cases, but you should only do so if advised that it's safe by a healthcare
professional.
If you cannot take aspirin, a
different medicine, such as paracetamol (for pain) or clopidogrel (to prevent blood clots),
may be recommended instead.
How a generic Aspirin tablet looks like.
How to take aspirin
Your pharmacist or doctor can tell you how often to take your aspirin and how much you should take. You can also check the recommendations in the leaflet that comes with your medicine.
Generally speaking:
- high-dose aspirin (to relieve pain) can
be taken three or four times a day, with at least four hours between each
dose, until your symptoms improve
- low-dose aspirin (to prevent blood clots) is
taken once a day, usually for the rest of your life.
Some medicine leaflets advise taking aspirin with
water, while others may recommend taking it before or after food.
Follow the instructions in the leaflet or label
that comes with your medicine. Ask your pharmacist if you are not sure.
Side effects of aspirin
The most common side effects are:
- indigestion and stomach aches – taking your
medicine with food may help reduce this risk
- bleeding
or bruising more easily than normal.
Uncommon and rare side effects include:
- hives – a raised, itchy rash
- tinnitus – hearing sounds that
come from inside your body
- breathing
difficulties or an asthma attack
- an
allergic reaction – this can cause breathing problems, swelling
of the mouth, lips or throat, and a sudden rash
- bleeding
in the stomach – this can cause dark, tar-like stools or vomiting blood
- bleeding
in the brain – this can cause a sudden, severe headache,
vision problems and stroke symptoms, such as slurred
speech and weakness on one side of the body.
You should speak to your doctor if you experience any
concerning or troublesome side effects while taking aspirin. You must call 999 for an ambulance or go to your nearest accident and emergency (A&E)
department if you think you're having a severe allergic
reaction, or you have symptoms of bleeding in your stomach or brain.
Interactions with other medicines, food and
alcohol
Aspirin can potentially interact with other medications, including some complementary and herbal medicines, which could alter their effects or increase your risk of side effects. Medicines that can interact with aspirin include:
- NSAIDs – such as
ibuprofen or naproxen
- steroid medication –
such as prednisolone
- anticoagulant medicines –
such as warfarin or heparin
- SSRI antidepressants –
such as citalopram, fluoxetine or paroxetine
- some medications used to treat high blood pressure –
such as ACE inhibitors or diuretics
- some medicines used to treat epilepsy –
such as phenytoin
- other medicines containing aspirin – including
cold and flu remedies where aspirin is one of the ingredients.
This is not a complete list. If you want to check
whether a medicine is safe to take with aspirin, ask your doctor or
pharmacist, or read the leaflet that comes with the medicine.
There are no known interactions between aspirin and food.
The risk of bleeding in the stomach may be
higher if you drink alcohol while taking aspirin, so you may want to consider
reducing how much you drink or avoiding alcohol completely.
Missed or extra doses
If you are taking aspirin to reduce your risk of blood clots and you forget to take a dose, take that dose as soon as you remember and then continue to take your course of aspirin as normal.
If it is almost time for the next dose, skip the
missed dose and continue your regular schedule. Don't take a double dose
to make up for a missed one. If you think you've taken too much aspirin
(overdose) and have any concerns, speak to your GP or pharmacist, or call NHS 111.
You should call 999 for an ambulance or go to your nearest
A&E department if you experience problems such as rapid breathing,
vomiting, tinnitus, sweating, or dizziness after an overdose.
Source: NHS Choices