Editing Trimethoprim (section)

==Side effects==

=== Common ===
* Nauseas
* Change in taste
* Vomiting
* Diarrhea
* Rashes
* Sun sensitivity
* Itchiness<ref name=":1">{{Cite web| work = DailyMed | title = PROLOPRIM® (trimethoprim)100-mg and 200-mg Scored Tablets|url = http://dailymed.nlm.nih.gov/dailymed/archives/fdaDrugInfo.cfm?archiveid=3220| publisher = U.S. National Library of Medicine |access-date = 4 November 2015|url-status = live|archive-url = https://web.archive.org/web/20151117015344/http://dailymed.nlm.nih.gov/dailymed/archives/fdaDrugInfo.cfm?archiveid=3220|archive-date = 17 November 2015}}</ref><ref>{{Cite book|title = American Hospital Formulary Service- Drug Information 2002.| vauthors = Ellenhorn MJ, Schonwald S, Ordog G, Wasserberger J |publisher = Williams and Wilkins|location = Baltimore, MD|pages = 236}}</ref>

=== Rare ===
* Can cause [[thrombocytopenia]] (low levels of [[platelets]]) by lowering [[folic acid]] levels; this may also cause [[megaloblastic anemia]].<ref name=":2">{{Cite book|title = Drug Information for the Health Care Professional | edition = 22nd | volume = 1 |last = MICROMEDEX Thomson Health Care. USPDI | publisher = Thomson Health Care |location = Greenwood Village, CO. | date = 2002 | page = 2849 }}</ref>
* Trimethoprim antagonizes the [[epithelial sodium channel]] <!-- (ENaC) --> in the [[distal tubule]], thus acting like [[amiloride]].  This can cause increased potassium levels in the body ([[hyperkalemia]]).<ref>{{cite journal | vauthors = Choi MJ, Fernandez PC, Patnaik A, Coupaye-Gerard B, D'Andrea D, Szerlip H, Kleyman TR | title = Brief report: trimethoprim-induced hyperkalemia in a patient with AIDS | journal = The New England Journal of Medicine | volume = 328 | issue = 10 | pages = 703–706 | date = March 1993 | pmid = 8433730 | doi = 10.1056/NEJM199303113281006 | doi-access = free }}</ref>
* Can compete with [[creatinine]] for secretion into the renal tubule.  This can cause an artificial rise in the serum creatinine.<ref>{{cite journal | vauthors = Naderer O, Nafziger AN, Bertino JS | title = Effects of moderate-dose versus high-dose trimethoprim on serum creatinine and creatinine clearance and adverse reactions | journal = Antimicrobial Agents and Chemotherapy | volume = 41 | issue = 11 | pages = 2466–2470 | date = November 1997 | pmid = 9371351 | pmc = 164146 | doi = 10.1128/AAC.41.11.2466 }}</ref>
* Use in [[Enterohemorrhagic Escherichia coli|EHEC]] infections may lead to an increase in expression of [[Shiga toxin]].<ref>{{cite journal | vauthors = Kimmitt PT, Harwood CR, Barer MR | title = Toxin gene expression by shiga toxin-producing Escherichia coli: the role of antibiotics and the bacterial SOS response | journal = Emerging Infectious Diseases | volume = 6 | issue = 5 | pages = 458–465 | year = 2000 | pmid = 10998375 | pmc = 2627954 | doi = 10.3201/eid0605.000503 }}</ref>

=== Contraindications ===
* Known [[hypersensitivity]] to trimethoprim
* History of [[megaloblastic anemia]] due to folate deficiency<ref name=":0">{{Cite web| work = DailyMed | title = PRIMSOL- trimethoprim hydrochloride solution|url = https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a06ea7d8-a884-4b62-a87f-c36d824f2aa4| publisher = U.S. National Library of Medicine  |access-date = 4 November 2015|url-status = live|archive-url = https://web.archive.org/web/20151117024132/https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a06ea7d8-a884-4b62-a87f-c36d824f2aa4|archive-date = 17 November 2015}}</ref><!-- supports all -->

It may be involved in a reaction similar to [[disulfiram]] when alcohol is consumed after it is used, in particular when used in combination with [[sulfamethoxazole]].<ref>{{cite journal | vauthors = Edwards DL, Fink PC, Van Dyke PO | title = Disulfiram-like reaction associated with intravenous trimethoprim-sulfamethoxazole and metronidazole | journal = Clinical Pharmacy | volume = 5 | issue = 12 | pages = 999–1000 | date = December 1986 | pmid = 3492326 | url = http://cat.inist.fr/?aModele=afficheN&cpsidt=8287529 | url-status = live | archive-url = https://web.archive.org/web/20090124113327/http://cat.inist.fr/?aModele=afficheN&cpsidt=8287529 | archive-date = 24 January 2009 }}</ref><ref>{{cite journal | vauthors = Heelon MW, White M | title = Disulfiram-cotrimoxazole reaction | journal = Pharmacotherapy | volume = 18 | issue = 4 | pages = 869–870 | year = 1998 | pmid = 9692665 | doi = 10.1002/j.1875-9114.1998.tb03913.x | url = http://cat.inist.fr/?aModele=afficheN&cpsidt=2340043 | url-status = live | s2cid = 23968977 | archive-url = https://web.archive.org/web/20090124113456/http://cat.inist.fr/?aModele=afficheN&cpsidt=2340043 | archive-date = 24 January 2009 }}</ref>

=== Pregnancy ===
Based on the studies that show that trimethoprim crosses the [[placenta]] and can affect folate metabolism, there has been growing evidence of the risk of structural birth defects associated with trimethoprim, especially during the first [[Pregnancy|trimester]] of pregnancy.<ref name="Sivojelezova 1085–1086">{{cite journal | vauthors = Sivojelezova A, Einarson A, Shuhaiber S, Koren G | title = Trimethoprim-sulfonamide combination therapy in early pregnancy | journal = Canadian Family Physician | volume = 49 | pages = 1085–1086 | date = September 2003 | pmid = 14526858 | pmc = 2214286 }}</ref>

The trophoblasts in the early fetus are sensitive to changes in the folate cycle. A 2013 study found a doubling in the risk of miscarriage in women exposed to trimethoprim in the early pregnancy.<ref>{{cite journal | vauthors = Andersen JT, Petersen M, Jimenez-Solem E, Broedbaek K, Andersen EW, Andersen NL, Afzal S, Torp-Pedersen C, Keiding N, Poulsen HE | title = Trimethoprim use in early pregnancy and the risk of miscarriage: a register-based nationwide cohort study | journal = Epidemiology and Infection | volume = 141 | issue = 8 | pages = 1749–1755 | date = August 2013 | pmid = 23010291 | pmc = 9151599 | doi = 10.1017/S0950268812002178 | s2cid = 19917493 }}</ref>