Editing Aspirin (section)

==Medical use==
Aspirin is used in the treatment of a number of conditions, including fever, pain, [[rheumatic fever]], and inflammatory conditions, such as [[rheumatoid arthritis]], [[pericarditis]], and [[Kawasaki disease]].<ref name=AHFS/> Lower doses of aspirin have also been shown to reduce the risk of death from a [[myocardial infarction|heart attack]], or the risk of [[stroke]] in people who are at high risk or who have cardiovascular disease, but not in elderly people who are otherwise healthy.<ref name="USFDA-patient-guideline">{{citation-attribution|1={{cite web |title=Aspirin for reducing your risk of heart attack and stroke: know the facts |url=https://www.fda.gov/drugs/safe-daily-use-aspirin/aspirin-reducing-your-risk-heart-attack-and-stroke-know-facts |publisher=U.S. [[Food and Drug Administration]] (FDA) |access-date=26 July 2012 |url-status=live |archive-url=https://web.archive.org/web/20120814182151/https://www.fda.gov/Drugs/ResourcesForYou/Consumers/BuyingUsingMedicineSafely/UnderstandingOver-the-CounterMedicines/SafeDailyUseofAspirin/ucm291433.htm |archive-date=14 August 2012}} }}</ref><ref name="USPSTF-CV">{{citation-attribution|1={{cite web |title=Aspirin for the prevention of cardiovascular disease |url=http://www.uspreventiveservicestaskforce.org/uspstf/uspsasmi.htm |publisher=[[United States Preventive Services Task Force]] |access-date=26 July 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120711031337/http://www.uspreventiveservicestaskforce.org/uspstf/uspsasmi.htm |archive-date=11 July 2012}} }}</ref><ref>{{cite journal | vauthors = Seshasai SR, Wijesuriya S, Sivakumaran R, Nethercott S, Erqou S, Sattar N, Ray KK | title = Effect of aspirin on vascular and nonvascular outcomes: meta-analysis of randomized controlled trials | journal = Archives of Internal Medicine | volume = 172 | issue = 3 | pages = 209–16 | date = February 2012 | pmid = 22231610 | doi = 10.1001/archinternmed.2011.628 | hdl-access = free | doi-access = free | hdl = 10044/1/34287 | title-link = doi }}</ref><ref name="NEJM-20180916">{{cite journal | vauthors = McNeil JJ, Woods RL, Nelson MR, Reid CM, Kirpach B, Wolfe R, Storey E, Shah RC, Lockery JE, Tonkin AM, Newman AB, Williamson JD, Margolis KL, Ernst ME, Abhayaratna WP, Stocks N, Fitzgerald SM, Orchard SG, Trevaks RE, Beilin LJ, Donnan GA, Gibbs P, Johnston CI, Ryan J, Radziszewska B, Grimm R, Murray AM | title = Effect of Aspirin on Disability-free Survival in the Healthy Elderly | journal = The New England Journal of Medicine | volume = 379 | issue = 16 | pages = 1499–1508 | date = October 2018 | pmid = 30221596 | pmc = 6426126 | doi = 10.1056/NEJMoa1800722 | hdl-access = free | doi-access = free | hdl = 1885/154654 | title-link = doi }}</ref><ref name=NEJM2018CVE>{{cite journal | vauthors = McNeil JJ, Wolfe R, Woods RL, Tonkin AM, Donnan GA, Nelson MR, Reid CM, Lockery JE, Kirpach B, Storey E, Shah RC, Williamson JD, Margolis KL, Ernst ME, Abhayaratna WP, Stocks N, Fitzgerald SM, Orchard SG, Trevaks RE, Beilin LJ, Johnston CI, Ryan J, Radziszewska B, Jelinek M, Malik M, Eaton CB, Brauer D, Cloud G, Wood EM, Mahady SE, Satterfield S, Grimm R, Murray AM | title = Effect of Aspirin on Cardiovascular Events and Bleeding in the Healthy Elderly | journal = The New England Journal of Medicine | volume = 379 | issue = 16 | pages = 1509–1518 | date = October 2018 | pmid = 30221597 | pmc = 6289056 | doi = 10.1056/NEJMoa1805819 | doi-access = free | title-link = doi }}</ref> There is evidence that aspirin is effective at preventing [[colorectal cancer]], though the mechanisms of this effect are unclear.<ref name="Algra 518–27">{{cite journal | vauthors = Algra AM, Rothwell PM | title = Effects of regular aspirin on long-term cancer incidence and metastasis: a systematic comparison of evidence from observational studies versus randomised trials | journal = The Lancet. Oncology | volume = 13 | issue = 5 | pages = 518–27 | date = May 2012 | pmid = 22440112 | doi = 10.1016/S1470-2045(12)70112-2 }}</ref>

===Pain===

Aspirin is an effective analgesic for acute pain, although it is generally considered inferior to [[ibuprofen]] because aspirin is more likely to cause [[gastrointestinal bleeding]].<ref name=pmid15768621>{{cite journal | vauthors = Sachs CJ | title = Oral analgesics for acute nonspecific pain | journal = American Family Physician | volume = 71 | issue = 5 | pages = 913–8 | date = March 2005 | pmid = 15768621 }}</ref> Aspirin is generally ineffective for those pains caused by muscle [[cramp]]s, [[bloating]], [[gastric distension]], or acute skin irritation.<ref name=pmid14592563>{{cite journal | vauthors = Gaciong Z | title = The real dimension of analgesic activity of aspirin | journal = Thrombosis Research | volume = 110 | issue = 5–6 | pages = 361–4 | date = June 2003 | pmid = 14592563 | doi = 10.1016/j.thromres.2003.08.009 }}</ref> As with other NSAIDs, [[Compound analgesic|combinations]] of aspirin and [[caffeine]] provide slightly greater pain relief than aspirin alone.<ref name=pmid22419343>{{cite journal | vauthors = Derry CJ, Derry S, Moore RA | title = Caffeine as an analgesic adjuvant for acute pain in adults | journal = The Cochrane Database of Systematic Reviews | volume = 2014 | issue = 12 | pages = CD009281 | date = December 2014 | pmid = 25502052 | pmc = 6485702 | doi = 10.1002/14651858.CD009281.pub3 }}</ref> [[Effervescent]] formulations of aspirin relieve pain faster than aspirin in tablets,<ref name=pmid10868553>{{cite journal | vauthors = Hersh EV, Moore PA, Ross GL | title = Over-the-counter analgesics and antipyretics: a critical assessment | journal = Clinical Therapeutics | volume = 22 | issue = 5 | pages = 500–48 | date = May 2000 | pmid = 10868553 | doi = 10.1016/S0149-2918(00)80043-0 }}</ref> which makes them useful for the treatment of [[migraine]]s.<ref name=pmid18451718>{{cite journal | vauthors = Mett A, Tfelt-Hansen P | title = Acute migraine therapy: recent evidence from randomized comparative trials | journal = Current Opinion in Neurology | volume = 21 | issue = 3 | pages = 331–7 | date = June 2008 | pmid = 18451718 | doi = 10.1097/WCO.0b013e3282fee843 | s2cid = 44459366 }}</ref> [[Topical medication|Topical]] aspirin may be effective for treating some types of [[neuropathic pain]].<ref>{{cite journal | vauthors = Kingery WS | title = A critical review of controlled clinical trials for peripheral neuropathic pain and complex regional pain syndromes | journal = Pain | volume = 73 | issue = 2 | pages = 123–139 | date = November 1997 | pmid = 9415498 | doi = 10.1016/S0304-3959(97)00049-3 | s2cid = 10418793 }}</ref>

Aspirin, either by itself or in a combined formulation, effectively treats certain [[Headache#Classification|types of a headache]], but its efficacy may be questionable for others. Secondary headaches, meaning those caused by another disorder or trauma, should be promptly treated by a medical provider. Among primary headaches, the [[International Classification of Headache Disorders]] distinguishes between [[tension headache]] (the most common), migraine, and [[cluster headache]]. Aspirin or other over-the-counter analgesics are widely recognized as effective for the treatment of tension headaches.<ref>{{cite journal | vauthors = Loder E, Rizzoli P | title = Tension-type headache | journal = BMJ | volume = 336 | issue = 7635 | pages = 88–92 | date = January 2008 | pmid = 18187725 | pmc = 2190284 | doi = 10.1136/bmj.39412.705868.AD }}</ref> Aspirin, especially as a component of an [[aspirin/paracetamol/caffeine]] [[combination drug|combination]], is considered a first-line therapy in the treatment of migraine, and comparable to lower doses of [[sumatriptan]]. It is most effective at stopping migraines when they are first beginning.<ref>{{cite journal | vauthors = Gilmore B, Michael M | title = Treatment of acute migraine headache | journal = American Family Physician | volume = 83 | issue = 3 | pages = 271–80 | date = February 2011 | pmid = 21302868 }}</ref>

===Fever===
Like its ability to control pain, aspirin's ability to control [[fever]] is due to its action on the [[prostaglandin]] system through its irreversible inhibition of [[COX]].<ref>{{cite journal | vauthors = Bartfai T, Conti B | title = Fever | journal = TheScientificWorldJournal | volume = 10 | pages = 490–503 | date = March 2010 | pmid = 20305990 | pmc = 2850202 | doi = 10.1100/tsw.2010.50 | doi-access = free }}</ref> Although aspirin's use as an [[antipyretic]] in adults is well established, many medical societies and regulatory agencies, including the [[American Academy of Family Physicians]], the [[American Academy of Pediatrics]], and the [[Food and Drug Administration]], strongly advise against using aspirin for the treatment of fever in children because of the risk of [[Reye syndrome]], a rare but often fatal illness associated with the use of aspirin or other salicylates in children during episodes of viral or bacterial infection.<ref>{{cite journal | vauthors = Pugliese A, Beltramo T, Torre D | title = Reye's and Reye's-like syndromes | journal = Cell Biochemistry and Function | volume = 26 | issue = 7 | pages = 741–6 | date = October 2008 | pmid = 18711704 | doi = 10.1002/cbf.1465 | s2cid = 22361194 }}</ref><ref>{{cite journal | vauthors = Beutler AI, Chesnut GT, Mattingly JC, Jamieson B | title = FPIN's Clinical Inquiries. Aspirin use in children for fever or viral syndromes | journal = American Family Physician | volume = 80 | issue = 12 | pages = 1472 | date = December 2009 | pmid = 20000310 }}</ref><ref name=AAPweb>{{cite web|title=Medications Used to Treat Fever|date=29 June 2012 |url=http://www.healthychildren.org/English/health-issues/conditions/fever/Pages/Medications-Used-to-Treat-Fever.aspx|publisher=American Academy of Pediatrics|access-date=25 November 2012|url-status=live|archive-url=https://web.archive.org/web/20130218084054/http://www.healthychildren.org/English/health-issues/conditions/fever/Pages/Medications-Used-to-Treat-Fever.aspx|archive-date=18 February 2013}}</ref> Because of the risk of Reye syndrome in children, in 1986, the US [[Food and Drug Administration]] (FDA) required labeling on all aspirin-containing medications advising against its use in children and teenagers.<ref name="FDA 1986 FR">{{cite journal|title=51 FR 8180|url=https://www.fda.gov/downloads/Drugs/DevelopmentApprovalProcess/DevelopmentResources/Over-the-CounterOTCDrugs/StatusofOTCRulemakings/UCM078593.pdf|journal=United States Federal Register|volume=51|issue=45|date=7 March 1986|url-status=dead|archive-url=https://web.archive.org/web/20110819130409/https://www.fda.gov/downloads/Drugs/DevelopmentApprovalProcess/DevelopmentResources/Over-the-CounterOTCDrugs/StatusofOTCRulemakings/UCM078593.pdf|archive-date=19 August 2011}}</ref>

===Inflammation===
Aspirin is used as an [[anti-inflammatory agent]] for both acute and long-term [[inflammation]],<ref name="pmid19597002">{{cite journal | vauthors = Morris T, Stables M, Hobbs A, de Souza P, Colville-Nash P, Warner T, Newson J, Bellingan G, Gilroy DW | title = Effects of low-dose aspirin on acute inflammatory responses in humans | journal = Journal of Immunology | volume = 183 | issue = 3 | pages = 2089–96 | date = August 2009 | pmid = 19597002 | doi = 10.4049/jimmunol.0900477 | doi-access = free | title-link = doi }}</ref> as well as for the treatment of inflammatory diseases, such as [[rheumatoid arthritis]].<ref name=AHFS />

===Heart attacks and strokes===
Aspirin is an important part of the treatment of those who have had a [[myocardial infarction|heart attack]].<ref>{{cite book | title = Myocardial infarction with ST-segment elevation: the acute management of myocardial infarction with ST-segment elevation [Internet] | series = NICE Clinical Guidelines | issue = 167 | date = July 2013 | pmid = 25340241 | chapter-url = https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0071000/ | url-status = live | archive-url = https://web.archive.org/web/20151231192814/http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0071000/ | archive-date = 31 December 2015 | at = 17.2 Aspirin | author1 = National Clinical Guideline Centre (UK) | chapter = Adjunctive pharmacotherapy and associated NICE guidance | publisher = Royal College of Physicians (UK) }}</ref> It is generally not recommended for routine use by people with no other health problems, including those over the age of 70.<ref name="Arnett-2019">{{cite journal | vauthors = Arnett DK, Blumenthal RS, Albert MA, Buroker AB, Goldberger ZD, Hahn EJ, Himmelfarb CD, Khera A, Lloyd-Jones D, McEvoy JW, Michos ED, Miedema MD, Muñoz D, Smith SC, Virani SS, Williams KA, Yeboah J, Ziaeian B | title = 2019 ACC/AHA Guideline on the Primary Prevention of Cardiovascular Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines | journal = Journal of the American College of Cardiology | volume = 74 | issue = 10 | pages = e177–e232 | date = September 2019 | pmid = 30894318 | pmc = 7685565 | doi = 10.1016/j.jacc.2019.03.010 | doi-access = free | title-link = doi }}</ref>

The 2009 Antithrombotic Trialists' Collaboration published in Lancet evaluated the efficacy and safety of low dose aspirin in secondary prevention. In those with prior ischaemic stroke or acute myocardial infarction, daily low dose aspirin was associated with a 19% relative risk reduction of serious cardiovascular events (non-fatal myocardial infarction, non-fatal stroke, or vascular death). This did come at the expense of a 0.19% absolute risk increase in gastrointestinal bleeding; however, the benefits outweigh the hazard risk in this case.{{citation needed|date=April 2023}} Data from previous trials have suggested that weight-based dosing of aspirin has greater benefits in primary prevention of cardiovascular outcomes.<ref name="Lancet2018Dose"/> However, more recent trials were not able to replicate similar outcomes using low dose aspirin in low body weight (<70&nbsp;kg) in specific subset of population studied i.e. elderly and diabetic population, and more evidence is required to study the effect of high dose aspirin in high body weight (≥70&nbsp;kg).<ref>{{cite journal | vauthors = Bowman L, Mafham M, Wallendszus K, Stevens W, Buck G, Barton J, Murphy K, Aung T, Haynes R, Cox J, Murawska A, Young A, Lay M, Chen F, Sammons E, Waters E, Adler A, Bodansky J, Farmer A, McPherson R, Neil A, Simpson D, Peto R, Baigent C, Collins R, Parish S, Armitage J | title = Effects of Aspirin for Primary Prevention in Persons with Diabetes Mellitus | journal = The New England Journal of Medicine | volume = 379 | issue = 16 | pages = 1529–1539 | date = October 2018 | pmid = 30146931 | doi = 10.1056/NEJMoa1804988 | doi-access = free | title-link = doi }}</ref><ref>{{cite journal | vauthors = McNeil JJ, Wolfe R, Woods RL, Tonkin AM, Donnan GA, Nelson MR, Reid CM, Lockery JE, Kirpach B, Storey E, Shah RC, Williamson JD, Margolis KL, Ernst ME, Abhayaratna WP, Stocks N, Fitzgerald SM, Orchard SG, Trevaks RE, Beilin LJ, Johnston CI, Ryan J, Radziszewska B, Jelinek M, Malik M, Eaton CB, Brauer D, Cloud G, Wood EM, Mahady SE, Satterfield S, Grimm R, Murray AM | title = Effect of Aspirin on Cardiovascular Events and Bleeding in the Healthy Elderly | journal = The New England Journal of Medicine | volume = 379 | issue = 16 | pages = 1509–1518 | date = October 2018 | pmid = 30221597 | doi = 10.1056/NEJMoa1805819 | pmc = 6289056 | doi-access = free | title-link = doi }}</ref><ref>{{cite journal | vauthors = Woods RL, Polekhina G, Wolfe R, Nelson MR, Ernst ME, Reid CM, Shah RC, Lockery JE, Orchard SG, Murray AM, McNeil JJ | title = No Modulation of the Effect of Aspirin by Body Weight in Healthy Older Men and Women | journal = Circulation | volume = 141 | issue = 13 | pages = 1110–1112 | date = March 2020 | pmid = 32223674 | doi = 10.1161/CIRCULATIONAHA.119.044142 | pmc = 7286412 | doi-access = free | title-link = doi }}</ref>

After [[percutaneous coronary intervention]]s (PCIs), such as the placement of a [[coronary artery]] [[stent]], a U.S. [[Agency for Healthcare Research and Quality]] guideline recommends that aspirin be taken indefinitely.<ref>{{cite web | author = National Guideline Clearinghouse (NGC) |title=2011 ACCF/AHA/SCAI guideline for percutaneous coronary artery intervention. A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines and the Society for Cardiovascular Angiography and Interventions |url=http://www.guideline.gov/content.aspx?id=34980 |url-status=dead |archive-url=https://web.archive.org/web/20120813064712/http://www.guideline.gov/content.aspx?id=34980 |archive-date=13 August 2012 |access-date=28 August 2012 |publisher=United States [[Agency for Healthcare Research and Quality]] (AHRQ)}}</ref> Frequently, aspirin is combined with an [[ADP receptor inhibitor]], such as [[clopidogrel]], [[prasugrel]], or [[ticagrelor]] to prevent [[Thrombosis|blood clots]]. This is called dual antiplatelet therapy (DAPT). Duration of DAPT was advised in the United States and European Union guidelines after the CURE<ref>{{cite journal |vauthors=Yusuf S, Zhao F, Mehta SR, Chrolavicius S, Tognoni G, Fox KK |date=August 2001 |title=Effects of clopidogrel in addition to aspirin in patients with acute coronary syndromes without ST-segment elevation |url=http://real.mtak.hu/12922/1/1277670.pdf |journal=The New England Journal of Medicine |volume=345 |issue=7 |pages=494–502 |doi=10.1056/nejmoa010746 |pmid=11519503|s2cid=15459216 }}</ref> and PRODIGY<ref>{{cite journal |vauthors=Costa F, Vranckx P, Leonardi S, Moscarella E, Ando G, Calabro P, Oreto G, Zijlstra F, Valgimigli M |date=May 2015 |title=Impact of clinical presentation on ischaemic and bleeding outcomes in patients receiving 6- or 24-month duration of dual-antiplatelet therapy after stent implantation: a pre-specified analysis from the PRODIGY (Prolonging Dual-Antiplatelet Treatment After Grading Stent-Induced Intimal Hyperplasia) trial |journal=European Heart Journal |volume=36 |issue=20 |pages=1242–51 |doi=10.1016/s0735-1097(15)61590-x |pmid=25718355 |doi-access=free |title-link=doi}}</ref> studies. In 2020, the systematic review and network meta-analysis from Khan et al.<ref>{{cite journal |vauthors=Khan SU, Singh M, Valavoor S, Khan MU, Lone AN, Khan MZ, Khan MS, Mani P, Kapadia SR, Michos ED, Stone GW, Kalra A, Bhatt DL |date=October 2020 |title=Dual Antiplatelet Therapy After Percutaneous Coronary Intervention and Drug-Eluting Stents: A Systematic Review and Network Meta-Analysis |journal=Circulation |volume=142 |issue=15 |pages=1425–1436 |doi=10.1161/CIRCULATIONAHA.120.046308 |pmc=7547897 |pmid=32795096}}</ref> showed promising benefits of short-term (< 6 months) DAPT followed by P2Y12 inhibitors in selected patients, as well as the benefits of extended-term (> 12 months) DAPT in high risk patients. In conclusion, the optimal duration of DAPT after PCIs should be personalized after outweighing each patient's risks of ischemic events and risks of bleeding events with consideration of multiple patient-related and procedure-related factors. Moreover, aspirin should be continued indefinitely after DAPT is complete.<ref>{{cite journal |vauthors=Capodanno D, Alfonso F, Levine GN, Valgimigli M, Angiolillo DJ |date=December 2018 |title=ACC/AHA Versus ESC Guidelines on Dual Antiplatelet Therapy: JACC Guideline Comparison |journal=Journal of the American College of Cardiology |volume=72 |issue=23 Pt A |pages=2915–2931 |doi=10.1016/j.jacc.2018.09.057 |pmid=30522654 |doi-access=free |title-link=doi}}</ref><ref>{{cite journal |vauthors=Levine GN, Bates ER, Bittl JA, Brindis RG, Fihn SD, Fleisher LA, Granger CB, Lange RA, Mack MJ, Mauri L, Mehran R, Mukherjee D, Newby LK, O'Gara PT, Sabatine MS, Smith PK, Smith SC |date=September 2016 |title=2016 ACC/AHA Guideline Focused Update on Duration of Dual Antiplatelet Therapy in Patients With Coronary Artery Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines |journal=Journal of the American College of Cardiology |volume=68 |issue=10 |pages=1082–115 |doi=10.1016/j.jacc.2016.03.513 |pmid=27036918 |doi-access=free |title-link=doi}}</ref><ref>{{cite journal |vauthors=Valgimigli M, Bueno H, Byrne RA, Collet JP, Costa F, Jeppsson A, Jüni P, Kastrati A, Kolh P, Mauri L, Montalescot G, Neumann FJ, Petricevic M, Roffi M, Steg PG, Windecker S, Zamorano JL, Levine GN |date=January 2018 |title=2017 ESC focused update on dual antiplatelet therapy in coronary artery disease developed in collaboration with EACTS: The Task Force for dual antiplatelet therapy in coronary artery disease of the European Society of Cardiology (ESC) and of the European Association for Cardio-Thoracic Surgery (EACTS) |journal=European Heart Journal |volume=39 |issue=3 |pages=213–260 |doi=10.1093/eurheartj/ehx419 |pmid=28886622 |doi-access=free |title-link=doi}}</ref>

The status of the use of aspirin for the primary prevention in cardiovascular disease is conflicting and inconsistent, with recent changes from previously recommending it widely decades ago, and that some referenced newer trials in clinical guidelines show less of benefit of adding aspirin alongside other anti-hypertensive and cholesterol lowering therapies.<ref name="Arnett-2019" /><ref name="Visseren-2021">{{cite journal | vauthors = Visseren FL, Mach F, Smulders YM, Carballo D, Koskinas KC, Bäck M, Benetos A, Biffi A, Boavida JM, Capodanno D, Cosyns B, Crawford C, Davos CH, Desormais I, Di Angelantonio E, Franco OH, Halvorsen S, Hobbs FD, Hollander M, Jankowska EA, Michal M, Sacco S, Sattar N, Tokgozoglu L, Tonstad S, Tsioufis KP, van Dis I, van Gelder IC, Wanner C, Williams B | title = 2021 ESC Guidelines on cardiovascular disease prevention in clinical practice | journal = European Heart Journal | volume = 42 | issue = 34 | pages = 3227–3337 | date = September 2021 | pmid = 34458905 | doi = 10.1093/eurheartj/ehab484 | doi-access = free }}</ref> The ASCEND study demonstrated that in high-bleeding risk diabetics with no prior cardiovascular disease, there is no overall clinical benefit (12% decrease in risk of ischaemic events v/s 29% increase in GI bleeding) of low dose aspirin in preventing the serious vascular events over a period of 7.4 years. Similarly, the results of the ARRIVE study also showed no benefit of same dose of aspirin in reducing the time to first cardiovascular outcome in patients with moderate risk of cardiovascular disease over a period of five years. Aspirin has also been suggested as a component of a [[polypill]] for prevention of cardiovascular disease.<ref name="pmid16100022">{{cite journal |vauthors=Norris JW |date=September 2005 |title=Antiplatelet agents in secondary prevention of stroke: a perspective |journal=Stroke |volume=36 |issue=9 |pages=2034–6 |doi=10.1161/01.STR.0000177887.14339.46 |pmid=16100022 |doi-access=free |title-link=doi}}</ref><ref name="pmid16603580">{{cite journal |vauthors=Sleight P, Pouleur H, Zannad F |date=July 2006 |title=Benefits, challenges, and registerability of the polypill |journal=European Heart Journal |volume=27 |issue=14 |pages=1651–6 |doi=10.1093/eurheartj/ehi841 |pmid=16603580 |doi-access=free |title-link=doi}}</ref> Complicating the use of aspirin for prevention is the phenomenon of aspirin resistance.<ref name="pmid16364973">{{cite journal |vauthors=Wang TH, Bhatt DL, Topol EJ |date=March 2006 |title=Aspirin and clopidogrel resistance: an emerging clinical entity |journal=European Heart Journal |volume=27 |issue=6 |pages=647–54 |doi=10.1093/eurheartj/ehi684 |pmid=16364973 |doi-access=free |title-link=doi}}</ref><ref name="pmid20944898">{{cite journal |vauthors=Oliveira DC, Silva RF, Silva DJ, Lima VC |date=September 2010 |title=Aspirin resistance: fact or fiction? |journal=Arquivos Brasileiros de Cardiologia |volume=95 |issue=3 |pages=e91-4 |doi=10.1590/S0066-782X2010001300024 |pmid=20944898 |doi-access=free |title-link=doi}}</ref> For people who are resistant, aspirin's efficacy is reduced.<ref name="pmid21306212">{{cite journal |vauthors=Topçuoglu MA, Arsava EM, Ay H |date=February 2011 |title=Antiplatelet resistance in stroke |journal=Expert Review of Neurotherapeutics |volume=11 |issue=2 |pages=251–63 |doi=10.1586/ern.10.203 |pmc=3086673 |pmid=21306212}}</ref> Some authors have suggested testing regimens to identify people who are resistant to aspirin.<ref name="pmid19576352">{{cite journal |vauthors=Ben-Dor I, Kleiman NS, Lev E |date=July 2009 |title=Assessment, mechanisms, and clinical implication of variability in platelet response to aspirin and clopidogrel therapy |journal=The American Journal of Cardiology |volume=104 |issue=2 |pages=227–33 |doi=10.1016/j.amjcard.2009.03.022 |pmid=19576352}}</ref>

As of {{as of|2022|April|lc=n|alt=|bare=yes}}, the [[United States Preventive Services Task Force]] (USPSTF) determined that there was a "small net benefit" for patients aged 40–59 with a 10% or greater 10-year cardiovascular disease (CVD) risk, and "no net benefit" for patients aged over 60.<ref>{{citation-attribution|{{cite web | title=Recommendation: Aspirin Use to Prevent Cardiovascular Disease: Preventive Medication | website=United States Preventive Services Taskforce | date=23 November 2020 | url=https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/aspirin-to-prevent-cardiovascular-disease-preventive-medication | access-date=5 May 2022}}}}</ref><ref>{{cite journal | vauthors = Davidson KW, Barry MJ, Mangione CM, Cabana M, Chelmow D, Coker TR, Davis EM, Donahue KE, Jaén CR, Krist AH, Kubik M, Li L, Ogedegbe G, Pbert L, Ruiz JM, Stevermer J, Tseng CW, Wong JB | title = Aspirin Use to Prevent Cardiovascular Disease: US Preventive Services Task Force Recommendation Statement | journal = JAMA | volume = 327 | issue = 16 | pages = 1577–1584 | date = April 2022 | pmid = 35471505 | doi = 10.1001/jama.2022.4983 | title-link = doi | doi-access = free }}</ref><ref>{{cite news | vauthors = Aubrey A, Stone W |date=26 April 2022 |title=Older adults shouldn't start a routine of daily aspirin, task force says |website=[[NPR]] |url=https://www.npr.org/sections/health-shots/2022/04/26/1094881056/older-adults-shouldnt-start-a-routine-of-daily-aspirin-task-force-says}}</ref> Determining the net benefit was based on balancing the risk reduction of taking aspirin for heart attacks and ischaemic strokes, with the increased risk of [[gastrointestinal bleeding]], [[Intracranial hemorrhage|intracranial bleeding]], and [[hemorrhagic stroke]]s. Their recommendations state that age changes the risk of the medicine, with the magnitude of the benefit of aspirin coming from starting at a younger age, while the risk of bleeding, while small, increases with age, particular for adults over 60, and can be compounded by other risk factors such as [[diabetes]] and a history of gastrointestinal bleeding. As a result, the USPSTF suggests that "people ages 40 to 59 who are at higher risk for CVD should decide with their clinician whether to start taking aspirin; people 60 or older should not start taking aspirin to prevent a first heart attack or stroke." Primary prevention guidelines from {{as of|2019|September|lc=n|alt=|bare=yes}} made by the [[American College of Cardiology]] and the [[American Heart Association]] state they might consider aspirin for patients aged 40–69 with a higher risk of atherosclerotic CVD, without an increased bleeding risk, while stating they would not recommend aspirin for patients aged over 70 or adults of any age with an increased bleeding risk.<ref name="Arnett-2019" /> They state a CVD risk estimation and a risk discussion should be done before starting on aspirin, while stating aspirin should be used "infrequently in the routine primary prevention of (atherosclerotic CVD) because of lack of net benefit". As of {{as of|2021|August|lc=n|alt=|bare=yes}}, the [[European Society of Cardiology]] made similar recommendations; considering aspirin specifically to patients aged less than 70 at high or very high CVD risk, without any clear contraindications, on a case-by-case basis considering both ischemic risk and bleeding risk.<ref name="Visseren-2021" />

===Cancer prevention===
Aspirin may reduce the overall risk of both getting cancer and dying from cancer.<ref name=Cuz2014>{{cite journal | vauthors = Cuzick J, Thorat MA, Bosetti C, Brown PH, Burn J, Cook NR, Ford LG, Jacobs EJ, Jankowski JA, La Vecchia C, Law M, Meyskens F, Rothwell PM, Senn HJ, Umar A | title = Estimates of benefits and harms of prophylactic use of aspirin in the general population | journal = Annals of Oncology | volume = 26 | issue = 1 | pages = 47–57 | date = January 2015 | pmid = 25096604 | pmc = 4269341 | doi = 10.1093/annonc/mdu225 }}</ref> There is substantial evidence for lowering the risk of [[colorectal cancer]] (CRC),<ref name="Algra 518–27"/><ref>{{cite journal | vauthors = Manzano A, Pérez-Segura P | title = Colorectal cancer chemoprevention: is this the future of colorectal cancer prevention? | journal = TheScientificWorldJournal | volume = 2012 | pages = 327341 | date = 29 April 2012 | pmid = 22649288 | pmc = 3353298 | doi = 10.1100/2012/327341 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Chan AT, Arber N, Burn J, Chia WK, Elwood P, Hull MA, Logan RF, Rothwell PM, Schrör K, Baron JA | title = Aspirin in the chemoprevention of colorectal neoplasia: an overview | journal = Cancer Prevention Research | volume = 5 | issue = 2 | pages = 164–78 | date = February 2012 | pmid = 22084361 | pmc = 3273592 | doi = 10.1158/1940-6207.CAPR-11-0391 }}</ref><ref>{{cite journal | vauthors = Thun MJ, Jacobs EJ, Patrono C | title = The role of aspirin in cancer prevention | journal = Nature Reviews. Clinical Oncology | volume = 9 | issue = 5 | pages = 259–67 | date = April 2012 | pmid = 22473097 | doi = 10.1038/nrclinonc.2011.199 | s2cid = 3332999 }}</ref> but aspirin must be taken for at least 10–20 years to see this benefit.<ref name="Richman2017">{{cite journal | vauthors = Richman IB, Owens DK | title = Aspirin for Primary Prevention | journal = The Medical Clinics of North America | volume = 101 | issue = 4 | pages = 713–724 | date = July 2017 | pmid = 28577622 | doi = 10.1016/j.mcna.2017.03.004 | type = Review }}</ref> It may also slightly reduce the risk of [[endometrial cancer]]<ref>{{cite journal | vauthors = Verdoodt F, Friis S, Dehlendorff C, Albieri V, Kjaer SK | title = Non-steroidal anti-inflammatory drug use and risk of endometrial cancer: A systematic review and meta-analysis of observational studies | journal = Gynecologic Oncology | volume = 140 | issue = 2 | pages = 352–8 | date = February 2016 | pmid = 26701413 | doi = 10.1016/j.ygyno.2015.12.009 }}</ref> and [[prostate cancer]].<ref>{{cite journal | vauthors = Bosetti C, Rosato V, Gallus S, Cuzick J, La Vecchia C | title = Aspirin and cancer risk: a quantitative review to 2011 | journal = Annals of Oncology | volume = 23 | issue = 6 | pages = 1403–15 | date = June 2012 | pmid = 22517822 | doi = 10.1093/annonc/mds113 | doi-access = free | title-link = doi }}</ref>

Some conclude the benefits are greater than the risks due to bleeding in those at average risk.<ref name=Cuz2014/> Others are unclear if the benefits are greater than the risk.<ref>{{cite journal|vauthors=Sutcliffe P, Connock M, Gurung T, Freeman K, Johnson S, Kandala NB, Grove A, Gurung B, Morrow S, Clarke A |date=September 2013|title=Aspirin for prophylactic use in the primary prevention of cardiovascular disease and cancer: a systematic review and overview of reviews|journal=[[Health Technology Assessment (journal)|Health Technology Assessment]]|volume=17|issue=43|pages=1–253|doi=10.3310/hta17430|pmc=4781046|pmid=24074752}}</ref><ref>{{cite journal | vauthors = Kim SE | title = The benefit-risk consideration in long-term use of alternate-day, low dose aspirin: focus on colorectal cancer prevention | journal = Annals of Gastroenterology | volume = 27 | issue = 1 | pages = 87–88 | date = 2014 | pmid = 24714632 | pmc = 3959543 }}</ref> Given this uncertainty, the 2007 [[United States Preventive Services Task Force]] (USPSTF) guidelines on this topic recommended against the use of aspirin for prevention of CRC in people with average risk.<ref name="USPSTF 2007">{{cite journal | title = Routine aspirin or nonsteroidal anti-inflammatory drugs for the primary prevention of colorectal cancer: U.S. Preventive Services Task Force recommendation statement | journal = Annals of Internal Medicine | volume = 146 | issue = 5 | pages = 361–4 | date = March 2007 | pmid = 17339621 | doi = 10.7326/0003-4819-146-5-200703060-00008 | doi-access = free | author1 = United States Preventive Services Task Force | title-link = doi }}</ref> Nine years later however, the USPSTF issued a grade B recommendation for the use of low-dose aspirin (75 to 100{{nbsp}}mg/day) "for the primary prevention of CVD [cardiovascular disease] and CRC in adults 50 to 59 years of age who have a 10% or greater 10-year CVD risk, are not at increased risk for bleeding, have a life expectancy of at least 10 years, and are willing to take low-dose aspirin daily for at least 10 years".<ref name="USPSTF 2016">{{cite journal |vauthors=Bibbins-Domingo K |date=June 2016 |title=Aspirin Use for the Primary Prevention of Cardiovascular Disease and Colorectal Cancer: U.S. Preventive Services Task Force Recommendation Statement |journal=Annals of Internal Medicine |volume=164 |issue=12 |pages=836–45 |doi=10.7326/m16-0577 |pmid=27064677 |doi-access=free |title-link=doi}}

* {{lay source|template=cite web|url=https://annals.org/aim/fullarticle/2513180/aspirin-use-primary-prevention-cardiovascular-disease-colorectal-cancer-recommendations-from|title=Who developed these recommendations?|date=21 June 2016|website=Annals of Internal Medicine}}</ref>

A meta-analysis through 2019 said that there was an association between taking aspirin and lower risk of cancer of the colorectum, esophagus, and stomach.<ref>{{cite journal | vauthors = Bosetti C, Santucci C, Gallus S, Martinetti M, La Vecchia C | title = Aspirin and the risk of colorectal and other digestive tract cancers: an updated meta-analysis through 2019 | journal = Annals of Oncology | volume = 31 | issue = 5 | pages = 558–568 | date = May 2020 | pmid = 32272209 | doi = 10.1016/j.annonc.2020.02.012 | quote = The present comprehensive meta-analysis supports and further quantifies the inverse association between regular aspirin use and the risk of colorectal and other digestive tract cancers, including some rare ones. The favorable effect of aspirin increases with longer duration of use, and, for colorectal cancer, with increasing dose. | doi-access = free | title-link = doi | hdl = 2434/730600 | hdl-access = free }}</ref>

In 2021, the [[United States Preventive Services Task Force]] raised questions about the use of aspirin in cancer prevention. It notes the results of the 2018 ASPREE (Aspirin in Reducing Events in the Elderly) Trial, in which the risk of cancer-related death was higher in the aspirin-treated group than in the placebo group.<ref>{{cite journal | vauthors = McNeil JJ, Nelson MR, Woods RL, Lockery JE, Wolfe R, Reid CM, Kirpach B, Shah RC, Ives DG, Storey E, Ryan J, Tonkin AM, Newman AB, Williamson JD, Margolis KL, Ernst ME, Abhayaratna WP, Stocks N, Fitzgerald SM, Orchard SG, Trevaks RE, Beilin LJ, Donnan GA, Gibbs P, Johnston CI, Radziszewska B, Grimm R, Murray AM | title = Effect of Aspirin on All-Cause Mortality in the Healthy Elderly | journal = The New England Journal of Medicine | volume = 379 | issue = 16 | pages = 1519–1528 | date = October 2018 | pmid = 30221595 | pmc = 6433466 | doi = 10.1056/NEJMoa1803955 }}</ref>

In 2025, a group of scientists at the [[University of Cambridge]] found that aspirin stimulates the immune system to reduce [[cancer metastasis]]. They found that a protein called [[ARHGEF1]] suppresses [[T cell]]s, that are required for attacking metastatic cancer cells. Aspirin appeared to counteract this suppression by targeting a clotting factor called [[thromboxane A2]] (TXA2), which activates ARHGEF1, thus preventing it from suppressing the T cells.<ref>{{cite journal | vauthors = Yang J, Yamashita-Kanemaru Y, Morris BI, Contursi A, Trajkovski D, Xu J, Patrascan I, Benson J, Evans AC, Conti AG, Al-Deka A, Dahmani L, Avdic-Belltheus A, Zhang B, Okkenhaug H, Whiteside SK, Imianowski CJ, Wesolowski AJ, Webb LV, Puccio S, Tacconelli S, Bruno A, Di Berardino S, De Michele A, Welch HC, Yu IS, Lin SW, Mitra S, Lugli E, van der Weyden L, Okkenhaug K, Saeb-Parsy K, Patrignani P, Adams DJ, Roychoudhuri R | title = Aspirin prevents metastasis by limiting platelet TXA<sub>2</sub> suppression of T cell immunity | journal = Nature | pages = 1052–1061 | date = March 2025 | volume = 640 | issue = 8060 | pmid = 40044852 | doi = 10.1038/s41586-025-08626-7 | doi-access = free | pmc = 12018268 }}</ref> The researchers called the discovery a "[[Eureka effect|Eureka]] moment".<ref>{{Cite web |date=2025-03-05 |title=Scientists describe 'Eureka moment' over how aspirin prevents cancer spread |url=https://www.independent.co.uk/news/health/scientists-university-of-cambridge-t-cells-medical-research-council-langley-b2709572.html |access-date=2025-03-05 |website=The Independent }}</ref> It was reported that the findings could lead to a more targeted use for aspirin in cancer research.<ref>{{Cite web |title=Scientists discover how aspirin could prevent some cancers from spreading |url=https://medicalxpress.com/news/2025-03-scientists-aspirin-cancers.html |access-date=2025-03-05 |website=Medical Xpress}}</ref> It was also said that taking self-medicating with aspirin should not be done yet due to its potential [[#Adverse effects|side effects]] until clinical trials were held.<ref>{{Cite web | vauthors = Cara E |date=2025-03-05 |title=A Surprising New Tool in the Fight Against Cancer: Aspirin |url=https://gizmodo.com/a-surprising-new-tool-in-the-fight-against-cancer-aspirin-2000571932 |access-date=2025-03-05 |website=Gizmodo }}</ref>

===Psychiatry===
====Bipolar disorder====
Aspirin, along with several other agents with anti-inflammatory properties, has been repurposed as an add-on treatment for depressive episodes in subjects with [[bipolar disorder]] in light of the possible role of inflammation in the pathogenesis of severe mental disorders.<ref name="repurposed2021">{{cite journal | vauthors = Bartoli F, Cavaleri D, Bachi B, Moretti F, Riboldi I, Crocamo C, Carrà G | title = Repurposed drugs as adjunctive treatments for mania and bipolar depression: A meta-review and critical appraisal of meta-analyses of randomized placebo-controlled trials | journal = Journal of Psychiatric Research | volume = 143 | pages = 230–238 | date = November 2021 | pmid = 34509090 | doi = 10.1016/j.jpsychires.2021.09.018 | s2cid = 237485915 }}</ref> A 2022 systematic review concluded that aspirin exposure reduced the risk of depression in a pooled cohort of three studies (HR 0.624, 95% CI: 0.0503, 1.198, P=0.033). However, further high-quality, longer-duration, double-blind randomized controlled trials (RCTs) are needed to determine whether aspirin is an effective add-on treatment for bipolar depression.<ref>{{cite journal | vauthors = Dominiak M, Gędek A, Sikorska M, Mierzejewski P, Wojnar M, Antosik-Wójcińska AZ | title = Acetylsalicylic Acid and Mood Disorders: A Systematic Review | journal = Pharmaceuticals | volume = 16 | issue = 1 | pages = 67 | date = December 2022 | pmid = 36678565 | pmc = 9861965 | doi = 10.3390/ph16010067 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Savitz JB, Teague TK, Misaki M, Macaluso M, Wurfel BE, Meyer M, Drevets D, Yates W, Gleason O, Drevets WC, Preskorn SH | title = Treatment of bipolar depression with minocycline and/or aspirin: an adaptive, 2×2 double-blind, randomized, placebo-controlled, phase IIA clinical trial | journal = Translational Psychiatry | volume = 8 | issue = 1 | pages = 27 | date = January 2018 | pmid = 29362444 | pmc = 5802452 | doi = 10.1038/s41398-017-0073-7 }}</ref><ref>{{cite journal | vauthors = Bauer IE, Green C, Colpo GD, Teixeira AL, Selvaraj S, Durkin K, Zunta-Soares GB, Soares JC | title = A Double-Blind, Randomized, Placebo-Controlled Study of Aspirin and N-Acetylcysteine as Adjunctive Treatments for Bipolar Depression | journal = The Journal of Clinical Psychiatry | volume = 80 | issue = 1 | date = December 2018 | pmid = 30549489 | doi = 10.4088/JCP.18m12200 | s2cid = 56483705 }}</ref> Thus, notwithstanding the biological rationale, the clinical perspectives of aspirin and anti-inflammatory agents in the treatment of bipolar depression remain uncertain.<ref name="repurposed2021"/>

====Dementia====
Although cohort and longitudinal studies have shown low-dose aspirin has a greater likelihood of reducing the incidence of dementia, numerous randomized controlled trials have not validated this.<ref>{{cite journal | vauthors = Li H, Li W, Zhang X, Ma XC, Zhang RW | title = Aspirin Use on Incident Dementia and Mild Cognitive Decline: A Systematic Review and Meta-Analysis | journal = Frontiers in Aging Neuroscience | volume = 12 | pages = 578071 | date = 4 February 2021 | pmid = 33613260 | pmc = 7890199 | doi = 10.3389/fnagi.2020.578071 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Veronese N, Stubbs B, Maggi S, Thompson T, Schofield P, Muller C, Tseng PT, Lin PY, Carvalho AF, Solmi M | title = Low-Dose Aspirin Use and Cognitive Function in Older Age: A Systematic Review and Meta-analysis | journal = Journal of the American Geriatrics Society | volume = 65 | issue = 8 | pages = 1763–1768 | date = August 2017 | pmid = 28425093 | pmc = 6810633 | doi = 10.1111/jgs.14883 }}</ref>

==== Schizophrenia ====
Some researchers have speculated the anti-inflammatory effects of aspirin may be beneficial for schizophrenia. Small trials have been conducted but evidence remains lacking.<ref>{{cite journal | vauthors = Schmidt L, Phelps E, Friedel J, Shokraneh F | title = Acetylsalicylic acid (aspirin) for schizophrenia | journal = The Cochrane Database of Systematic Reviews | volume = 2019 | issue = 8 | pages = CD012116 | date = August 2019 | pmid = 31425623 | pmc = 6699651 | doi = 10.1002/14651858.CD012116.pub2 }}</ref><ref>{{cite journal | vauthors = Fond G, Lançon C, Korchia T, Auquier P, Boyer L | title = The Role of Inflammation in the Treatment of Schizophrenia | journal = Frontiers in Psychiatry | volume = 11 | pages = 160 | date = 2020 | pmid = 32256401 | doi = 10.3389/fpsyt.2020.00160 | pmc = 7093323 | doi-access = free }}</ref>

===Other uses===
Aspirin is a first-line treatment for the fever and joint-pain symptoms of [[rheumatic fever|acute rheumatic fever]]. The therapy often lasts for one to two weeks, and is rarely indicated for longer periods. After fever and pain have subsided, the aspirin is no longer necessary, since it does not decrease the incidence of heart complications and residual rheumatic heart disease.<ref name=NHFA>{{cite web |url=http://www.racgp.org.au/Content/NavigationMenu/ClinicalResources/RACGPGuidelines/DiagnosisandmanagementofacuterheumaticfeverandrheumaticheartdiseaseinAustralia/NHFA-CSANZ_ARF_RHD_2006.pdf |archive-url=https://web.archive.org/web/20080726052030/http://www.racgp.org.au/Content/NavigationMenu/ClinicalResources/RACGPGuidelines/DiagnosisandmanagementofacuterheumaticfeverandrheumaticheartdiseaseinAustralia/NHFA-CSANZ_ARF_RHD_2006.pdf |archive-date=26 July 2008 |title=Diagnosis and management of acute rheumatic fever and rheumatic heart disease in Australia. An evidence-based review |author=[[National Heart Foundation of Australia]] (RF/RHD guideline development working group) and the Cardiac Society of Australia and New Zealand |year=2006 |publisher=National Heart Foundation of Australia |pages=33–37}}</ref><ref>{{cite journal | vauthors = Saxena A, Kumar RK, Gera RP, Radhakrishnan S, Mishra S, Ahmed Z | title = Consensus guidelines on pediatric acute rheumatic fever and rheumatic heart disease | journal = Indian Pediatrics | volume = 45 | issue = 7 | pages = 565–73 | date = July 2008 | pmid = 18695275 }}</ref> [[Naproxen]] has been shown to be as effective as aspirin and less toxic, but due to the limited clinical experience, naproxen is recommended only as a second-line treatment.<ref name=NHFA/><ref>{{cite journal | vauthors = Hashkes PJ, Tauber T, Somekh E, Brik R, Barash J, Mukamel M, Harel L, Lorber A, Berkovitch M, Uziel Y | title = Naproxen as an alternative to aspirin for the treatment of arthritis of rheumatic fever: a randomized trial | journal = The Journal of Pediatrics | volume = 143 | issue = 3 | pages = 399–401 | date = September 2003 | pmid = 14517527 | doi = 10.1067/S0022-3476(03)00388-3 }}</ref>

Along with rheumatic fever, [[Kawasaki disease]] remains one of the few indications for aspirin use in children<ref>{{cite journal | vauthors = Rowley AH, Shulman ST | title = Pathogenesis and management of Kawasaki disease | journal = Expert Review of Anti-Infective Therapy | volume = 8 | issue = 2 | pages = 197–203 | date = February 2010 | pmid = 20109049 | pmc = 2845298 | doi = 10.1586/eri.09.109 }}</ref> in spite of a lack of high quality evidence for its effectiveness.<ref>{{cite journal | vauthors = Baumer JH, Love SJ, Gupta A, Haines LC, Maconochie I, Dua JS | title = Salicylate for the treatment of Kawasaki disease in children | journal = The Cochrane Database of Systematic Reviews | issue = 4 | pages = CD004175 | date = October 2006 | volume = 2010 | pmid = 17054199 | doi = 10.1002/14651858.CD004175.pub2 | pmc = 8765111 }}</ref>

Low-dose aspirin supplementation has moderate benefits when used for prevention of [[pre-eclampsia]].<ref>{{cite journal | vauthors = Duley L, Meher S, Hunter KE, Seidler AL, Askie LM | title = Antiplatelet agents for preventing pre-eclampsia and its complications | journal = The Cochrane Database of Systematic Reviews | volume = 2019 | issue = 10 | date = October 2019 | pmid = 31684684 | pmc = 6820858 | doi = 10.1002/14651858.CD004659.pub3 }}</ref><ref name=Roberge_2012>{{cite journal | vauthors = Roberge S, Villa P, Nicolaides K, Giguère Y, Vainio M, Bakthi A, Ebrashy A, Bujold E | title = Early administration of low-dose aspirin for the prevention of preterm and term preeclampsia: a systematic review and meta-analysis | journal = Fetal Diagnosis and Therapy | volume = 31 | issue = 3 | pages = 141–6 | year = 2012 | pmid = 22441437 | doi = 10.1159/000336662 | s2cid = 26372982 | doi-access = free | title-link = doi }}</ref> This benefit is greater when started in early pregnancy.<ref>{{cite journal | vauthors = Roberge S, Nicolaides K, Demers S, Hyett J, Chaillet N, Bujold E | title = The role of aspirin dose on the prevention of preeclampsia and fetal growth restriction: systematic review and meta-analysis | journal = American Journal of Obstetrics and Gynecology | volume = 216 | issue = 2 | pages = 110–120.e6 | date = February 2017 | pmid = 27640943 | doi = 10.1016/j.ajog.2016.09.076 | s2cid = 3079979 }}</ref>

Aspirin has also demonstrated [[Treatment of cancer|anti-tumoral]] effects, via inhibition of the [[PTTG1]] gene, which is often overexpressed in tumors.<ref>{{cite journal|title=Aspirin Mediates Its Antitumoral Effect Through Inhibiting PTTG1 in Pituitary Adenoma|doi=10.1210/clinem/dgac496|doi-access=free|journal=[[The Journal of Clinical Endocrinology and Metabolism]]|vauthors=Szabó B, Németh K, Mészáros K, Krokker L, Likó I, Saskői E, Németh K, Szabó PT, Szücs N, Czirják S, Szalóki G, Patócs A, Butz H|date=5 September 2022|volume=107|issue=11|pages=3066–3079|pmid=36059148 |pmc=9681612 }}</ref>

===Resistance===
{{see also|Drug tolerance}}
For some people, aspirin does not have as strong an effect on platelets as for others, an effect known as aspirin-resistance or insensitivity. One study has suggested women are more likely to be resistant than men,<ref>{{cite journal | vauthors = Dorsch MP, Lee JS, Lynch DR, Dunn SP, Rodgers JE, Schwartz T, Colby E, Montague D, Smyth SS | title = Aspirin resistance in patients with stable coronary artery disease with and without a history of myocardial infarction | journal = The Annals of Pharmacotherapy | volume = 41 | issue = 5 | pages = 737–41 | date = May 2007 | pmid = 17456544 | doi = 10.1345/aph.1H621 | s2cid = 22245507 }}</ref> and a different, aggregate study of 2,930 people found 28% were resistant.<ref name="pmid18202034">{{cite journal | vauthors = Krasopoulos G, Brister SJ, Beattie WS, Buchanan MR | title = Aspirin "resistance" and risk of cardiovascular morbidity: systematic review and meta-analysis | journal = BMJ | volume = 336 | issue = 7637 | pages = 195–8 | date = January 2008 | pmid = 18202034 | pmc = 2213873 | doi = 10.1136/bmj.39430.529549.BE }}</ref>
A study in 100 Italian people found, of the apparent 31% aspirin-resistant subjects, only 5% were truly resistant, and the others were [[Compliance (medicine)|noncompliant]].<ref name="pmid18680540">{{cite journal | vauthors = Pignatelli P, Di Santo S, Barillà F, Gaudio C, Violi F | title = Multiple anti-atherosclerotic treatments impair aspirin compliance: effects on aspirin resistance | journal = Journal of Thrombosis and Haemostasis | volume = 6 | issue = 10 | pages = 1832–4 | date = October 2008 | pmid = 18680540 | doi = 10.1111/j.1538-7836.2008.03122.x | s2cid = 1776526 | doi-access = free | title-link = doi }}</ref>
Another study of 400 healthy volunteers found no subjects who were truly resistant, but some had "pseudoresistance, reflecting delayed and reduced drug absorption".
<ref>{{cite journal | vauthors = Grosser T, Fries S, Lawson JA, Kapoor SC, Grant GR, FitzGerald GA | title = Drug resistance and pseudoresistance: an unintended consequence of enteric coating aspirin | journal = Circulation | volume = 127 | issue = 3 | pages = 377–85 | date = January 2013 | pmid = 23212718 | pmc = 3552520 | doi = 10.1161/CIRCULATIONAHA.112.117283 }}
*{{lay source |template = cite news|vauthors = Thomas K|url= https://www.nytimes.com/2012/12/05/business/coating-on-buffered-aspirin-may-hide-its-heart-protective-effects.html|title = Study Raises Questions on Coating of Aspirin|date = 4 December 2012|website = [[The New York Times]] }}</ref>

Meta-analysis and systematic reviews have concluded that laboratory confirmed aspirin resistance confers increased rates of poorer outcomes in cardiovascular and neurovascular diseases.<ref>{{cite journal | vauthors = Li J, Song M, Jian Z, Guo W, Chen G, Jiang G, Wang J, Wu X, Huang L | title = Laboratory aspirin resistance and the risk of major adverse cardiovascular events in patients with coronary heart disease on confirmed aspirin adherence | journal = Journal of Atherosclerosis and Thrombosis | volume = 21 | issue = 3 | pages = 239–47 | date = 2014 | pmid = 24201035 | doi = 10.5551/jat.19521 | doi-access = free | title-link = doi }}</ref><ref name="pmid18202034"/><ref>{{cite journal | vauthors = Sofi F, Marcucci R, Gori AM, Abbate R, Gensini GF | title = Residual platelet reactivity on aspirin therapy and recurrent cardiovascular events--a meta-analysis | journal = International Journal of Cardiology | volume = 128 | issue = 2 | pages = 166–71 | date = August 2008 | pmid = 18242733 | doi = 10.1016/j.ijcard.2007.12.010 | hdl-access = free | hdl = 2158/323452 }}</ref><ref>{{cite journal | vauthors = Shim EJ, Ryu CW, Park S, Lee HN, Shin HS, Kim SB | title = Relationship between adverse events and antiplatelet drug resistance in neurovascular intervention: a meta-analysis | journal = Journal of NeuroInterventional Surgery | volume = 10 | issue = 10 | pages = 942–948 | date = October 2018 | pmid = 29352056 | doi = 10.1136/neurintsurg-2017-013632 | s2cid = 38147668 }}</ref><ref>{{cite journal | vauthors = Fiolaki A, Katsanos AH, Kyritsis AP, Papadaki S, Kosmidou M, Moschonas IC, Tselepis AD, Giannopoulos S | title = High on treatment platelet reactivity to aspirin and clopidogrel in ischemic stroke: A systematic review and meta-analysis | journal = Journal of the Neurological Sciences | volume = 376 | pages = 112–116 | date = May 2017 | pmid = 28431593 | doi = 10.1016/j.jns.2017.03.010 | s2cid = 3485236 }}</ref><ref>{{cite journal | vauthors = Snoep JD, Hovens MM, Eikenboom JC, van der Bom JG, Huisman MV | title = Association of laboratory-defined aspirin resistance with a higher risk of recurrent cardiovascular events: a systematic review and meta-analysis | journal = Archives of Internal Medicine | volume = 167 | issue = 15 | pages = 1593–9 | date = 13 August 2007 | pmid = 17698681 | doi = 10.1001/archinte.167.15.1593 | doi-access = free | title-link = doi }}</ref> Although the majority of research conducted has surrounded cardiovascular and neurovascular, there is emerging research into the risk of aspirin resistance after orthopaedic surgery where aspirin is used for venous thromboembolism prophylaxis.<ref name="A Narrative Review of Aspirin Resis">{{cite journal | vauthors = van Oosterom N, Barras M, Bird R, Nusem I, Cottrell N | title = A Narrative Review of Aspirin Resistance in VTE Prophylaxis for Orthopaedic Surgery | journal = Drugs | volume = 80 | issue = 18 | pages = 1889–1899 | date = December 2020 | pmid = 33037568 | doi = 10.1007/s40265-020-01413-w | s2cid = 222234431 }}</ref> Aspirin resistance in orthopaedic surgery, specifically after total hip and knee arthroplasties, is of interest as risk factors for aspirin resistance are also risk factors for venous thromboembolisms and osteoarthritis; the sequelae of requiring a total hip or knee arthroplasty. Some of these risk factors include obesity, advancing age, diabetes mellitus, dyslipidemia and inflammatory diseases.<ref name="A Narrative Review of Aspirin Resis"/>