Antiplatelets, aspirin, low dose

Antiplatelets, aspirin, low dose

Introduction

Aspirin is an antiplatelet medicine, which means it reduces the risk of clots forming in your blood. This reduces your risk of having a stroke or heart attack.

Normally, when there is a cut or break in a small blood vessel, a blood clot forms to plug the hole until the blood vessel heals.

Small cells in the blood called platelets make the blood clot. When a platelet detects a damaged area of a blood vessel, it produces a chemical that attracts other platelets and makes them stick together to form a blood clot.

Aspirin reduces the ability of the platelets to stick together and reduces the risk of clots forming.

When is low-dose aspirin used?

Low-dose aspirin (usually 75mg a day) may be given to you if you have had:

It may also be given to you if you are considered at risk of having a heart attack or stroke. You may be considered at risk if you:

Treatment with an antiplatelet medicine such as aspirin is usually for life.

Higher doses of aspirin may be given for other conditions, but these pages focus on the use of low-dose aspirin.

Children

Aspirin may be given to children under specialist supervision after heart surgery, or to treat children with Kawasaki disease.

Aspirin must not be given to anyone under 16 years old, unless under specialist advice.

Things to consider

You should not take aspirin if you have certain health conditions, such as a peptic ulcer or bleeding disorder.

You should also use aspirin with caution if you have certain conditions, such as asthma or uncontrolled high blood pressure.

Low-dose aspirin (75mg) may be taken if you are pregnant or breastfeeding, but only on the recommendation of your GP.

Read more detailed information about things to consider before taking aspirin.

Side effects and interactions

Although serious reactions are rare, aspirin can cause side effects such as indigestion. In more serious cases it can cause vomiting, an allergic reaction or bleeding in the stomach.

See your doctor if you are worried or continue to experience any side effects while taking low-dose aspirin.

Read more information about the side effects of aspirin.

Aspirin can interact with many other medicines. Always read the patient information leaflet that comes with your medicine to check that it is safe to take with aspirin. If you are unsure, ask your pharmacist or GP.

Read more information about other medicines that can interact with aspirin.

Missed doses

If you forget to take your dose of aspirin, take that dose as soon as you remember and then continue to take your course of aspirin as normal.

However, if it is almost time for the next dose, skip the missed dose and continue your regular schedule. Do not take a double dose to make up for a missed one.

Extra doses

The patient information leaflet that comes with your medicine includes advice about what to do if you miss a dose.

If you accidentally take an extra dose of low-dose aspirin, it is unlikely to cause you harm as larger doses of aspirin are given safely for other conditions.

However, if you feel unwell or are concerned, speak to your GP or pharmacist, or call NHS 111.

Special considerations

Aspirin may not be suitable to take if you have certain health conditions.

When to avoid aspirin

Low-dose aspirin should not be taken if you:

Aspirin must not be given to anyone under 16 years old, unless under specialist advice.

Pregnancy and breastfeeding

If you are pregnant or breastfeeding, only take low-dose aspirin (75mg) on the recommendation of your doctor.

It is also important not to take aspirin at doses higher than 100mg per day during the last three months of pregnancy because this can lead to complications in the mother or baby.

Using aspirin with caution

Tell your doctor before taking low-dose aspirin if you have:

Occasionally, some people are advised to stop taking aspirin seven days before a planned operation. For some people this may include minor surgery, such as a tooth extraction. Seek advice from your doctor or surgeon before you stop taking any medication.

Side effects of aspirin

Aspirin can cause side effects, although serious reactions are rare.

See your doctor if you are worried or continue to experience any side effects while taking low-dose aspirin.

Common side effects may include: 

However, less than 10% of people taking aspirin experience these side effects. If you experience indigestion, try sticking to basic food and taking your aspirin after a meal.

Allergic reaction

In some cases aspirin can cause an allergic reaction, although this is more common in people who have asthma. Go to the nearest hospital’s accident and emergency department (A&E) if you experience:

  • swelling of the lips, mouth or throat
  • breathing problems
  • a skin rash which appears quickly

Uncommon or rare side effects

Other, rarer side effects of aspirin may include:

  • a runny nose
  • headache
  • ringing in the ears (tinnitus)
  • vertigo
  • a raised, itchy rash on the skin (hives)
  • nausea or vomiting
  • worsening of asthma caused by narrowing of airways
  • inflammation (swelling) of the stomach
  • bleeding in the stomach
  • bruising

In extremely rare cases, a possible side effect of taking low-dose aspirin is haemorrhagic stroke (bleeding in the brain).

Reporting side effects

The Yellow Card Scheme allows you to report suspected side effects from any type of medicine you are taking.

It is run by a medicines safety watchdog called the Medicines and Healthcare products Regulatory Agency (MHRA). See the website of the Yellow Card Scheme for more information.

Interactions with other medicines

Aspirin can interact with many different types of medication, which could alter their effects or increase your risk of serious side effects.

Some of the more common interactions are listed below. However, this is not a complete list.

If you want to check your medicines are safe to take with aspirin, ask your doctor or pharmacist, or read the patient information leaflet that comes with your medicine.

Medicines that could interact with aspirin include:

Interactions with food and alcohol

There are no known interactions between aspirin and food.

However, it is a good idea to take aspirin with or after food, to help reduce irritation to the stomach.

It may be safe to drink alcohol with some painkillers that can be bought over the counter, as long as you:

  • check the patient information leaflet that comes with the medicine
  • take the correct dose of your medicine
  • do not drink more than the maximum recommended daily limits of alcohol

Taking more than the recommended dose of aspirin or ibuprofen increases the risk of irritation to your stomach lining. This risk is increased further if you drink more than the recommended daily limits of alcohol (it may lead to bleeding from the stomach).