Editing Aspirin (section)

===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"/>