Summary of UK guidelines for aspirin

August 2023
The purpose of this document is to keep a working list of UK guidelines with information on aspirin. The guidelines themselves should be read for further information.


Venous thromboembolism in over 16s: reducing the risk of hospital-acquired deep vein thrombosis or pulmonary embolism NICE

NICE guideline Published: 21 March 2018 Last updated: 13 August 2019

NICE guidelines state that aspirin can be considered as one of several options ( see full guideline for alternative options) for the following scenarios:

Pharmacological VTE prophylaxis for people with myeloma who are receiving chemotherapy with thalidomide, pomalidomide or lenalidomide with steroids (aspirin 75 mg or 150 mg off label)

VTE prophylaxis for people undergoing elective hip replacement surgery whose risk of VTE outweighs their risk of bleeding (LMWH for 10 days followed by aspirin (75 mg or 150 mg for a further 28 days off label)

VTE prophylaxis to people undergoing elective hip replacement surgery whose risk of VTE outweighs their risk of bleeding (LMWH for 10 days followed by aspirin 75 mg or 150 mg for a further 28 days off label)

They make the following recommendations for research

Jenny, J. , Pabinger, I. & Samama, C. M. (2018). European guidelines on perioperative venous thromboembolism prophylaxis. European Journal of Anaesthesiology, 35 (2), 123-129. doi: 10.1097/EJA.000000000000072


Primary prevention of cardiovascular disease

NICE CKS Antiplatelet treatment for primary prevention of cardiovascular disease [Last revised August 2020] “Do not routinely prescribe antiplatelet treatment for the primary prevention of cardiovascular disease (CVD).” It then states, “Consider prescribing aspirin in people with a high risk of stroke or myocardial infarction.” The guidelines remind readers that aspirin is not licensed for the primary prevention of CVD and that people can reduce their CVD risk by other means such as smoking cessation or taking at statin. The guidelines emphasise “if aspirin is being considered, discuss the likely benefits (reduced CVD risk) and risks (such as gastrointestinal bleeding) with the person.”
For further information see:
NICE also recommend reading their advice on managing antiplatelet-induced dyspepsia:


Secondary prevention of cardiovascular disease

NICE CKS Antiplatelet treatment for the secondary prevention of CVD [last revised August 2020] suggests antiplatelet treatment for people who have had:

Guidance around managing dyspepsia including Heliocobacter pylori testing and PPI usage is also included. The guidelines explain that risk factors for having a GI bleed include:

Please see
For further information about aspirin for secondary CVD prevention.
NICE Acute coronary syndromes guidelines



Chest pain

NICE CG95 March 2010 [last updated Nov 2016] recent-onset chest pain of suspected cardiac origin: assessment and diagnosis states that people with suspected acute coronary syndrome should be offered a loading dose of 300 mg of aspirin as soon as possible [unless they are allergic to it]. If this is achieved before hospitalisation a written record that is has been given should be sent with the patient.


Stroke and TIA

NICE NG128 May 2019 Stroke and transient ischaemic attack in over 16s: diagnosis and initial management.
1.1.4. “Offer aspirin (300 mg daily), unless contraindicated, to people who have had a suspected TIA, to be started immediately.’
Further information about this decision can be found at:
The same guidelines recommend aspirin for people with acute ischaemic stroke, as soon as possible within 24 hours, where a diagnosis of intracerebral haemorrhage has been excluded using brain imaging. For those without dysphagia give aspirin 300 mg orally and those with dysphagia can be give the same dose rectally or via an enteral tube. Aspirin 300 mg daily should be continued until long term antithrombotic treatment is agreed 2 weeks post stroke or at discharge.
A proton pump inhibitor is recommended in addition to aspirin for those with dyspepsia linked to aspirin use.
For further details on aspirin use and stroke read the full guidance.


Atrial fibrillation (AF)

NICE Atrial Fibrillation: diagnosis and management (NG196) (Published 27 April 2021) states that ‘for most people the benefit of anticoagulation outweighs the bleeding risk.’ They recommend offering anticoagulation with a direct-acting oral anticoagulant (DOAC), to adults with AF and a CHA2DS2-VASc score of 2 or more. Offer warfarin if a DOAC such as apixaban, dabigatran, edoxaban and rivaroxaban are contraindicated or not tolerated. The guidelines state that aspirin monotherapy should not be offered solely for the purposes of stroke prevention in people with AF. NICE offer guidance for antiplatelet therapy in people with a separate indication for anticoagulant therapy in their NICE (NG185) Acute coronary syndromes guidelines. .


Prevention of cardiovascular events in diabetics

NICE NG17 2015 (updated December 2020) states “Do not offer aspirin for the primary prevention of cardiovascular disease to adults with type 1 diabetes.”
NICE NG28 2015 (updated December 2020) Type 2 diabetes in adults- management state “Do not offer antiplatelet therapy (aspirin or clopidogrel) for adults with type 2 diabetes without cardiovascular disease.”


Primary prevention of colorectal cancer/all GI cancers

NICE NG151 Colorectal cancer guidelines recommend daily aspirin for 2 years or more to help prevent colorectal cancer in people with Lynch syndrome.
The guidance explains that this is an off-label use of aspirin, they do not make a recommendation on exact dose as work is ongoing to establish this however, they observe that commonly used doses of aspirin in current practice are 150 mg or 300 mg. Further information on the recommendation explains that the multi-country randomised controlled trial used 600 mg of aspirin daily for more than 2 years. Further information on the NICE evidence review for aspirin use in the prevention of colorectal cancer in people with Lynch syndrome can be found at:
In order to help people with Lynch syndrome decide if they would like to take daily aspirin to help reduce the chance of developing bowel cancer NICE have produced a patient decision aid.


Aspirin and pre-eclampsia

The International Federation of Gynaecology and Obstetrics recommend that women identified as high risk of pre-eclampsia during first trimester screening should be given aspirin prophylaxis (150mg at night from 11-14 weeks gestation until delivery or the diagnosis of pre-eclampsia). They do not advocate a policy of low-dose aspirin for all pregnant women.
Poon LC, Shennan A, Hyett JA et al The International federation of Gynaecology and Obstetrics (FIGO) initiative on pre-eclampsia: a pragmatic guide for first-trimester screening and prevention. Int J Gynecol Obstet 2019; 145 (Suppl.1) 1-33. @
A Cochrane review from 2019 concluded that low dose aspirin does slightly reduce the risk of pre-eclampsia and its complications but that further research is required to identify those most likely to benefit.
Duley L, Meher S and Hunter KE et al. Antiplatelet agents for preventing pre-eclampsia and its complications Cochrane Database of Systematic Reviews Oct 2019
NICE 2019 recommends that women who are at high risk of pre-eclampsia take 75-150mg of aspirin daily from 12 weeks until the birth of the baby. They define women at high risk as those with; hypertension during a previous pregnancy, chronic kidney disease, an auto immune disease (e.g. systemic lupus erythematosus or antiphospholipid syndrome), diabetes (type 1 or 2) and/or chronic hypertension. In addition, they advise women with more than one moderate risk factor for pre-eclampsia to take low-dose aspirin from 12 weeks until birth. Moderate risk factors for pre-eclampsia are; first pregnancy, age 40 or above, a pregnancy interval of more than 10 years, obesity, family history of pre-eclampsia and a multiple foetus pregnancy.
NICE NG133 Hypertension in pregnancy: diagnosis and management. 2019 @
Further resources
Antiplatelet treatment: Low dose aspirin last revised August 2020