Editing Metronidazole (section)

==Medical uses==
[[File:Metronidazole Aurobindo tube.jpg|left|thumb|A tube of metronidazole cream]]
Metronidazole has activity against some [[protozoan]]s and most [[anaerobic bacteria]] (both [[Gram-negative bacteria|Gram-negative]] and [[Gram-positive bacteria|Gram-positive]] classes) but not the [[aerobic bacteria]].<ref name="pmid9360057">{{cite journal |vauthors=Freeman CD, Klutman NE, Lamp KC |title=Metronidazole. A therapeutic review and update |journal=Drugs |volume=54 |issue=5 |pages=679–708 |date=November 1997 |pmid=9360057 |doi=10.2165/00003495-199754050-00003}}</ref><ref name="pmid20067388">{{cite journal |vauthors=Löfmark S, Edlund C, Nord CE |title=Metronidazole is still the drug of choice for treatment of anaerobic infections |journal=Clin Infect Dis |volume=50 |issue= Suppl 1|pages=S16–23 |date=January 2010 |pmid=20067388 |doi=10.1086/647939|doi-access=free }}</ref>

Metronidazole is primarily used to treat: [[bacterial vaginosis]], [[pelvic inflammatory disease]] (along with other antibacterials like [[ceftriaxone]]), [[pseudomembranous colitis]], [[aspiration pneumonia]], [[rosacea]] (topical), fungating wounds (topical), intra-abdominal infections, [[lung abscess]], [[periodontal disease]], [[amoebiasis]], oral infections, [[giardiasis]], [[trichomoniasis]], and infections caused by susceptible anaerobic organisms such as ''[[Bacteroides]], [[Fusobacterium]], [[Clostridium]], [[Peptostreptococcus]]'', and ''[[Prevotella]]'' species.<ref name = AMH/> It is also often used to eradicate ''[[Helicobacter pylori]]'' along with other drugs and to prevent infection in people recovering from surgery.<ref name = AMH/>

Metronidazole is bitter and so the liquid suspension contains metronidazole benzoate. This may require [[hydrolysis]] in the gastrointestinal tract and some sources speculate that it may be unsuitable in people with diarrhea or feeding-tubes in the duodenum or jejunum.<ref name="Geoghegan-2017">{{cite web |url = https://www.pharmaceutical-journal.com/learning/cpd-article/clostridium-difficile-diagnosis-and-treatment-update/20202242.cpdarticle |title = ''Clostridium difficile'': diagnosis and treatment update |publisher = Royal Pharmaceutical Society |vauthors = Geoghegan O, Eades C, Moore LS, Gilchrist M |work = The Pharmaceutical Journal |date = 9 February 2017 |access-date = 22 January 2018 |archive-date = 7 March 2019 |archive-url = https://web.archive.org/web/20190307054301/https://www.pharmaceutical-journal.com/learning/cpd-article/clostridium-difficile-diagnosis-and-treatment-update/20202242.cpdarticle |url-status = live }}</ref><ref name="Dickman-2012">{{cite book |vauthors = Dickman A |title=Drugs in Palliative Care |date=2012 |publisher=OUP Oxford |isbn=978-0-19-163610-3 |page=355 |url=https://books.google.com/books?id=mSzs_8ijZpgC&pg=PA355 |access-date=29 August 2020 |archive-date=25 June 2022 |archive-url=https://web.archive.org/web/20220625064231/https://books.google.com/books?id=mSzs_8ijZpgC&pg=PA355 |url-status=live }}</ref>

===Bacterial vaginosis===
Drugs of choice for the treatment of bacterial vaginosis include metronidazole and [[clindamycin]].<ref name="pmid10028110">{{cite journal |vauthors = Joesoef MR, Schmid GP, Hillier SL |title = Bacterial vaginosis: review of treatment options and potential clinical indications for therapy |journal = Clinical Infectious Diseases |volume = 28 |issue = Suppl 1 |pages = S57–S65 |date = January 1999 |pmid = 10028110 |doi = 10.1086/514725 |title-link = doi |doi-access = free }}</ref>

An effective treatment option for mixed infectious vaginitis is a combination of clotrimazole and metronidazole.<ref name="pmid37773671">{{cite journal |vauthors=Huang Y, Shen C, Shen Y, Cui H |title=Assessing the Efficacy of Clotrimazole and Metronidazole Combined Treatment in Vaginitis: A Meta-Analysis |journal=Altern Ther Health Med |volume=30 |issue=1 |pages=186–191 |date=January 2024 |pmid=37773671}}</ref>

===Trichomoniasis===
The [[5-nitroimidazole]] drugs (metronidazole and [[tinidazole]]) are the mainstay of treatment for infection with ''[[Trichomonas vaginalis]]''. Treatment for both the infected patient and the patient's sexual partner is recommended, even if asymptomatic. Therapy other than 5-nitroimidazole drugs is also an option, but cure rates are much lower.<ref name="pmid9132982">{{cite journal |vauthors = duBouchet L, Spence MR, Rein MF, Danzig MR, McCormack WM |title = Multicenter comparison of clotrimazole vaginal tablets, oral metronidazole, and vaginal suppositories containing sulfanilamide, aminacrine hydrochloride, and allantoin in the treatment of symptomatic trichomoniasis |journal = Sexually Transmitted Diseases |volume = 24 |issue = 3 |pages = 156–160 |date = March 1997 |pmid = 9132982 |doi = 10.1097/00007435-199703000-00006 |s2cid = 6617019 |doi-access = free }}</ref>

===Giardiasis===
Oral metronidazole is a treatment option for [[giardiasis]], however, the increasing incidence of [[nitroimidazole]] resistance is leading to the increased use of other compound classes.<ref name="pmid26258002">{{cite journal |vauthors = Leitsch D |title = Drug Resistance in the Microaerophilic Parasite ''Giardia lamblia'' |journal = Current Tropical Medicine Reports |volume = 2 |issue = 3 |pages = 128–135 |date = September 2015 |pmid = 26258002 |pmc = 4523694 |doi = 10.1007/s40475-015-0051-1 }}</ref>

===Dracunculus===
In the case of ''[[Dracunculus medinensis]]'' (Guinea worm), metronidazole merely facilitates worm extraction rather than killing the worm.<ref name=AHFS2015/>

===''C. difficile'' colitis===
Initial antibiotic therapy for less-severe ''[[Clostridioides difficile infection]]'' colitis ([[pseudomembranous colitis]]) consists of metronidazole, [[vancomycin]], or [[fidaxomicin]] by mouth.<ref name="pmid29462280"/> In 2017, the IDSA generally recommended vancomycin and fidaxomicin over metronidazole.<ref name="pmid29462280"/> Vancomycin [[Oral administration|by mouth]] has been shown to be more effective in treating people with severe ''C. difficile'' colitis.<ref name="pmid17599306">{{cite journal |vauthors = Zar FA, Bakkanagari SR, Moorthi KM, Davis MB |title = A comparison of vancomycin and metronidazole for the treatment of Clostridium difficile-associated diarrhea, stratified by disease severity |journal = Clinical Infectious Diseases |volume = 45 |issue = 3 |pages = 302–307 |date = August 2007 |pmid = 17599306 |doi = 10.1086/519265 |title-link = doi |doi-access = free }}</ref>

=== ''E. histolytica'' ===
''[[Entamoeba histolytica]]'' invasive [[Amoebiasis|amebiasis]] is treated with metronidazole for eradication, in combination with [[diloxanide]] to prevent recurrence.<ref name="Ryan-2018">{{cite book |title=Sherris medical microbiolog |isbn=978-1-259-85981-6 |edition= Seventh |location=New York | publisher = McGraw Hill LLC |oclc=1004770160 |vauthors = Ryan KJ, Ahmad N, Alspaugh JA, Drew WL, Lagunoff M, Pottinger P, Reller LB, Reller ME, Sterling CR, Weissman S |date = 12 January 2018}}</ref> Although it is generally a standard treatment it is associated with some side effects.<ref name="pmid32356312">{{cite journal |vauthors = Rawat A, Singh P, Jyoti A, Kaushik S, Srivastava VK |title = Averting transmission: A pivotal target to manage amoebiasis |journal = Chemical Biology & Drug Design |volume = 96 |issue = 2 |pages = 731–744 |date = August 2020 |pmid = 32356312 |doi = 10.1111/cbdd.13699 |s2cid = 218475533 }}</ref>

===Preterm births===
Metronidazole has also been used in women to prevent [[preterm birth]] associated with bacterial vaginosis, amongst other risk factors including the presence of cervicovaginal fetal fibronectin (fFN). Metronidazole was ineffective in preventing preterm delivery in high-risk pregnant women (selected by history and a positive fFN test) and, conversely, the incidence of preterm delivery was found to be higher in women treated with metronidazole.<ref name="pmid16398774">{{cite journal |vauthors = Shennan A, Crawshaw S, Briley A, Hawken J, Seed P, Jones G, Poston L |title = A randomised controlled trial of metronidazole for the prevention of preterm birth in women positive for cervicovaginal fetal fibronectin: the PREMET Study |journal = BJOG |volume = 113 |issue = 1 |pages = 65–74 |date = January 2006 |pmid = 16398774 |doi = 10.1111/j.1471-0528.2005.00788.x |s2cid = 11366650 }}</ref>

===Hypoxic radiosensitizer===
In addition to its anti-biotic properties, attempts were also made to use a possible [[Radiosensitizer|radiation-sensitizing effect]] of metronidazole in the context of radiation therapy against [[Tumor hypoxia#Radiotherapy|hypoxic tumors]].<ref name="pmid6884824">{{cite journal | vauthors = Nori D, Cain JM, Hilaris BS, Jones WB, Lewis JL | title = Metronidazole as a radiosensitizer and high-dose radiation in advanced vulvovaginal malignancies, a pilot study | journal = Gynecologic Oncology | volume = 16 | issue = 1 | pages = 117–28 | date = August 1983 | pmid = 6884824 | doi = 10.1016/0090-8258(83)90017-3 }}</ref> However, the neurotoxic side effects occurring at the required dosages have prevented the widespread use of metronidazole as an adjuvant agent in radiation therapy.<ref name="Sarna_2013">{{cite journal | vauthors = Sarna JR, Furtado S, Brownell AK | title = Neurologic complications of metronidazole | journal = The Canadian Journal of Neurological Sciences | volume = 40 | issue = 6 | pages = 768–776 | date = November 2013 | pmid = 24257215 | doi = 10.1017/s0317167100015870 }}</ref> However, other [[nitroimidazole]]s derived from metronidazole such as [[nimorazole]] with reduced electron affinity showed less serious neuronal side effects and have found their way into radio-onological practice for head and neck tumors in some countries.<ref name="Overgaard_1998">{{cite journal | vauthors = Overgaard J, Hansen HS, Overgaard M, Bastholt L, Berthelsen A, Specht L, Lindeløv B, Jørgensen K | title = A randomized double-blind phase III study of nimorazole as a hypoxic radiosensitizer of primary radiotherapy in supraglottic larynx and pharynx carcinoma. Results of the Danish Head and Neck Cancer Study (DAHANCA) Protocol 5-85 | journal = Radiotherapy and Oncology | volume = 46 | issue = 2 | pages = 135–46 | date = February 1998 | pmid = 9510041 | doi = 10.1016/s0167-8140(97)00220-x }}</ref>

=== Perioral dermatitis ===
''[[Canadian Family Physician]]'' has recommended topical metronidazole as a third-line treatment for the [[perioral dermatitis]] either along with or without oral [[tetracycline]] or oral [[erythromycin]] as first and second line treatment respectively.<ref name="pmid15856972">{{cite journal |vauthors = Cheung MJ, Taher M, Lauzon GJ |title = Acneiform facial eruptions: a problem for young women |journal = Canadian Family Physician |volume = 51 |pages = 527–533 |date = April 2005 |issue = 4 |pmid = 15856972 |pmc = 1472951 }}</ref>