Editing Contraceptive patch (section)

===Thromboembolism===
All combined [[hormonal birth control]] products have a very small increased risk of serious or fatal [[thrombosis|thromboembolic]] events. There is ongoing research into the thromboembolic risks of Ortho Evra as compared to combined oral contraceptive pills. A recent study found that users of the contraceptive patch may have a twofold increased risk for non-fatal venous thromboembolic events compared with women who took a norgestimate-containing oral contraceptive with 35&nbsp;μg of estrogen.<ref name="Alert">Medpage Today. [http://www.medpagetoday.com/ProductAlert/Prescriptions/tb/2697 Evidence on Ortho Evra Patch Thrombosis Risk Is Contradictory] {{Webarchive|url=https://web.archive.org/web/20060301110459/http://www.medpagetoday.com/ProductAlert/Prescriptions/tb/2697 |date=2006-03-01 }}. Published February 17, 2006.</ref><ref name="Cole2007">{{cite journal | vauthors = Cole JA, Norman H, Doherty M, Walker AM | title = Venous thromboembolism, myocardial infarction, and stroke among transdermal contraceptive system users | journal = Obstetrics and Gynecology | volume = 109 | issue = 2 Pt 1 | pages = 339–346 | date = February 2007 | pmid = 17267834 | doi = 10.1097/01.AOG.0000250968.82370.04 | s2cid = 1572286 }}</ref> However, a different study concluded that the risk of nonfatal venous thromboembolism for the contraceptive patch is similar to the risk for oral contraceptives containing 35&nbsp;μg of ethinylestradiol and [[norgestimate]].<ref name="Contraception">{{cite journal | vauthors = Jick S, Kaye JA, Li L, Jick H | title = Further results on the risk of nonfatal venous thromboembolism in users of the contraceptive transdermal patch compared to users of oral contraceptives containing norgestimate and 35 microg of ethinyl estradiol | journal = Contraception | volume = 76 | issue = 1 | pages = 4–7 | date = July 2007 | pmid = 17586129 | doi = 10.1016/j.contraception.2007.03.003 }}</ref> The contradiction in findings between the two studies is not easily resolved, because the [[confidence interval]]s for the studies are overlapping.

In studies with oral contraceptives, the risk for cardiovascular disease (such as thromboembolism) is significantly increased in women over the age of 35 years who also [[Tobacco smoking|smoke tobacco]].<ref name="smoking">{{cite journal | vauthors = Pitsavos C, Stefanadis C, Toutouzas P | title = Contraception in women at high risk or with established cardiovascular disease | journal = Annals of the New York Academy of Sciences | volume = 900 | issue = 1 | pages = 215–227 | year = 2000 | pmid = 10818409 | doi = 10.1111/j.1749-6632.2000.tb06233.x | s2cid = 45035196 | bibcode = 2000NYASA.900..215P }}</ref>  Hence, Ortho Evra's package insert states: "Women who use hormonal contraceptives, including Ortho Evra, should be strongly advised not to smoke."

According to the manufacturer, the patches introduce a 60% higher level of estrogen into the bloodstream as compared to oral contraceptives; however, the clinical significance of this difference is unknown.{{medical citation needed|date=February 2020}}

On November 10, 2005, Ortho McNeil, in conjunction with the [[U.S. Food and Drug Administration|FDA]], revised the label for Ortho Evra, including a new bolded warning about higher exposure to estrogen for women using the weekly patch compared to taking a daily birth control pill containing 35&nbsp;μg of estrogen, noting that higher levels of estrogen may put some women at increased risk for getting blood clots. The label was again revised in September 2006, and on January 18, 2008, the FDA again updated the label to reflect study results: "The FDA believes that Ortho Evra is a safe and effective method of contraception when used according to the labeling, which recommends that women with concerns or risk factors for serious blood clots talk with their health care provider about using Ortho Evra versus other contraceptive options."<ref name="FDA2008">[https://web.archive.org/web/20080120221214/http://www.fda.gov/bbs/topics/NEWS/2008/NEW01781.html FDA Approves Update to Label on Birth Control Patch]. FDA. January 18, 2008 </ref>