View source for Flunixin

{{Short description|NSAID analgesic veterinary drug}}
{{Drugbox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 447383576
| IUPAC_name = 2-<nowiki>[[</nowiki>2-Methyl-3-(trifluoromethyl)phenyl]amino]pyridine-3-carboxylic acid
| image = Flunixin Structural Formulae V.1.svg
| image_class = skin-invert-image
| ChEMBL_Ref = {{ebicite|changed|EBI}}
| ChEMBL = 1652146

<!--Clinical data-->
| tradename = 
| Drugs.com = {{drugs.com|international|flunixin}}
| pregnancy_AU = <!-- A / B1 / B2 / B3 / C / D / X -->
| pregnancy_US = <!-- A / B            / C / D / X -->
| pregnancy_category = 
| legal_AU = <!-- S2, S3, S4, S5, S6, S7, S8, S9 or Unscheduled-->
| legal_CA = <!-- Schedule I, II, III, IV, V, VI, VII, VIII -->
| legal_UK = <!-- GSL, P, POM, CD, or Class A, B, C -->
| legal_US = <!-- OTC / Rx-only / Schedule I, II, III, IV, V -->
| legal_status = 
| routes_of_administration =

<!--Pharmacokinetic data-->
| bioavailability = 
| protein_bound = 
| metabolism = 
| elimination_half-life = 
| excretion =

<!--Identifiers-->
| CAS_number_Ref = {{cascite|correct|??}}
| CAS_number = 38677-85-9
| ATCvet = yes
| ATC_prefix = M01
| ATC_suffix = AG90
| PubChem = 38081
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank = 
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 356IB1O400
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D04215
| ChEBI_Ref = {{ebicite|changed|EBI}}
| ChEBI = 76138
|  ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
| ChemSpiderID = 34911
|  smiles = CC1=C(C=CC=C1NC2=C(C=CC=N2)C(=O)O)C(F)(F)F
|  StdInChI_Ref = {{stdinchicite|changed|chemspider}}
| StdInChI = 1S/C14H11F3N2O2/c1-8-10(14(15,16)17)5-2-6-11(8)19-12-9(13(20)21)4-3-7-18-12/h2-7H,1H3,(H,18,19)(H,20,21)
|  StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
| StdInChIKey = NOOCSNJCXJYGPE-UHFFFAOYSA-N

<!--Chemical data-->
| C=14 | H=11 | F=3 | N=2 | O=2
}}

'''Flunixin''' is a [[nonsteroidal anti-inflammatory drug]] (NSAID), [[analgesic]], and [[antipyretic]] used in horses, cattle and pigs. It is often formulated as the [[meglumine]] [[salt (chemistry)|salt]].  In the United States, it is regulated by the [[Food and Drug Administration (United States)|U.S. Food and Drug Administration]] (FDA), and may only be lawfully distributed by order of a licensed veterinarian. There are many trade names for the product.

==Dosage and uses in horses==
Flunixin is administered at a dose of 1.1&nbsp;mg/kg.<ref name="McIlwraith">{{cite journal | vauthors = McIlwraith CW, Frisbie DD, Kawcak CE | title = Nonsteroidal Anti-Inflammatory Drugs  | journal = Proc. AAEP | date = 2001 | volume = 47 | pages = 182–187 }}</ref> The full analgesic and antipyretic effects usually occur 1–2 hours following treatment, but there is often an effective analgesic effect within approximately 15 minutes. Despite its short [[biological half life|plasma half life]] of 1.6–2.5 hours, effects can persist for up to 30 hours,<ref>{{cite book | vauthors = May SA, Lees P | chapter = Nonsteroidal anti-inflammatory drugs | veditors = McIlwraith CW, Trotter GW | title = Joint Disease in the Horse | location = Philadelphia | publisher = WB Saunders | date = 1996 | pages = 223–237 }}</ref> with maximal effects occurring between 2 and 16 hours. This is likely due to accumulation of the drug at inflammatory foci. Flunixin is primarily eliminated by the kidneys.<ref name="pmid3247913">{{cite journal | vauthors = Soma LR, Behrend E, Rudy J, Sweeney RW | title = Disposition and excretion of flunixin meglumine in horses | journal = American Journal of Veterinary Research | volume = 49 | issue = 11 | pages = 1894–8 | date = November 1988 | pmid = 3247913 }}</ref>

Because it targets the inflamed tissue, flunixin is mainly used for [[colic]] pain, musculoskeletal pain, and ocular pain.<ref name="Foreman_2012">{{cite journal | vauthors = Foreman JH, Bergstrom BE, Golden KS, Roark JJ, Coren DS, Foreman CR, Schumacher SA | title = Dose titration of the clinical efficacy of intravenously administered flunixin meglumine in a reversible model of equine foot lameness | journal = Equine Veterinary Journal. Supplement | issue = 43 | pages = 17–20 | date = December 2012 | volume = 44 | pmid = 23447872 | doi = 10.1111/j.2042-3306.2012.00655.x | doi-access = free }}</ref><ref name="pmid9118091">{{cite journal | vauthors = Jochle W, Moore JN, Brown J, Baker GJ, Lowe JE, Fubini S, Reeves MJ, Watkins JP, White NA | title = Comparison of detomidine, butorphanol, flunixin meglumine and xylazine in clinical cases of equine colic | journal = Equine Veterinary Journal. Supplement | issue = 7 | pages = 111–6 | date = June 1989 | volume = 21 | pmid = 9118091 | doi = 10.1111/j.2042-3306.1989.tb05668.x }}</ref><ref name="pmid21781166">{{cite journal | vauthors = Hilton HG, Magdesian KG, Groth AD, Knych H, Stanley SD, Hollingsworth SR | title = Distribution of flunixin meglumine and firocoxib into aqueous humor of horses | journal = Journal of Veterinary Internal Medicine | volume = 25 | issue = 5 | pages = 1127–33 | date = 2011 | pmid = 21781166 | doi = 10.1111/j.1939-1676.2011.0763.x | doi-access = free }}</ref> It is also used as an [[antipyretic]] and to reduce the effects of [[endotoxemia]].<ref name="pmid12602591">{{cite journal | vauthors = Bryant CE, Farnfield BA, Janicke HJ | title = Evaluation of the ability of carprofen and flunixin meglumine to inhibit activation of nuclear factor kappa B | journal = American Journal of Veterinary Research | volume = 64 | issue = 2 | pages = 211–5 | date = February 2003 | pmid = 12602591 | doi = 10.2460/ajvr.2003.64.211 | doi-access = free }}</ref>

==Side effects and precautions==
Flunixin is labeled for no more than 5 days of consecutive use and prolonged use increases the risk of toxicity. In horses, this includes [[equine gastric ulcer syndrome|gastric ulcers]],<ref name="pmid19580940">{{cite journal | vauthors = Videla R, Andrews FM | title = New perspectives in equine gastric ulcer syndrome | journal = The Veterinary Clinics of North America. Equine Practice | volume = 25 | issue = 2 | pages = 283–301 | date = August 2009 | pmid = 19580940 | doi = 10.1016/j.cveq.2009.04.013 }}</ref> right dorsal colitis,<ref name="pmid18980433">{{cite journal | vauthors = McConnico RS, Morgan TW, Williams CC, Hubert JD, Moore RM | title = Pathophysiologic effects of phenylbutazone on the right dorsal colon in horses | journal = American Journal of Veterinary Research | volume = 69 | issue = 11 | pages = 1496–505 | date = November 2008 | pmid = 18980433 | doi = 10.2460/ajvr.69.11.1496 | doi-access = free }}</ref> and [[nephrotoxicity]].<ref name="pmid3487106">{{cite journal | vauthors = Black HE | title = Renal toxicity of non-steroidal anti-inflammatory drugs | journal = Toxicologic Pathology | volume = 14 | issue = 1 | pages = 83–90 | date = 1986 | pmid = 3487106 | doi = 10.1177/019262338601400110 | s2cid = 28865193 }}</ref>

Flunixin is a prohibited substance under [[International Federation for Equestrian Sports]] rules,<ref>{{cite web|title=FEI Prohibited Substances List|date=28 October 2013 |url=http://www.fei.org/fei/cleansport/ad-h/prohibited-list|access-date=23 January 2016}}</ref> and its use is prohibited or restricted by many other equestrian organizations. At labeled dose (1.1&nbsp;mg/kg) given IV, detection time was found to be 144 hours.<ref>{{cite web|title=FEI List of Detection Times|url=http://www.fei.org/system/files/FEI%20detection%20times%20lab%202015.pdf|access-date=23 January 2016}}</ref> However, drug recycling from bedding contamination by treated horses has been shown to potentially increase the clearance time.<ref name="pmid21995754">{{cite journal | vauthors = Popot MA, Garcia P, Bonnaire Y | title = Doping control in horses: housing conditions and oral recycling of flunixin by ingestion of contaminated straw | journal = Journal of Veterinary Pharmacology and Therapeutics | volume = 34 | issue = 6 | pages = 612–4 | date = December 2011 | pmid = 21995754 | doi = 10.1111/j.1365-2885.2011.01276.x }}</ref>

==Administration==
Flunixin may be given orally as a paste, as granules in feed, or intravenously(IV). It is strongly recommended that it not be administered intramuscularly (IM) as it is very irritating to tissue and IM administration has been associated with [[gas gangrene|myonecrosis]] in horses,<ref name="pmid12553469">{{cite journal | vauthors = Peek SF, Semrad SD, Perkins GA | title = Clostridial myonecrosis in horses (37 cases 1985-2000) | journal = Equine Veterinary Journal | volume = 35 | issue = 1 | pages = 86–92 | date = January 2003 | pmid = 12553469 | doi = 10.2746/042516403775467513 }}</ref> so IV administration is preferred.

Administration of [[phenylbutazone]] to a horse also receiving flunixin has been shown to increase the risk of toxicity without improving analgesia.<ref name="pmid22082440">{{cite journal | vauthors = Foreman JH, Ruemmler R | title = Phenylbutazone and flunixin meglumine used singly or in combination in experimental lameness in horses | journal = Equine Veterinary Journal. Supplement | issue = 40 | pages = 12–7 | date = November 2011 | volume = 43 | pmid = 22082440 | doi = 10.1111/j.2042-3306.2011.00485.x | doi-access = free }}</ref><ref name="pmid16506899">{{cite journal | vauthors = Reed SK, Messer NT, Tessman RK, Keegan KG | title = Effects of phenylbutazone alone or in combination with flunixin meglumine on blood protein concentrations in horses | journal = American Journal of Veterinary Research | volume = 67 | issue = 3 | pages = 398–402 | date = March 2006 | pmid = 16506899 | doi = 10.2460/ajvr.67.3.398 }}</ref> For this reason, concurrent administration with another NSAID is not recommended. Doubling the dose of flunixin produces no improvement in analgesia, while potentially increasing the risk of toxicity.<ref name="Foreman_2012" />

In the US, the only labeled route for flunixin administration in cattle is intravenous and pour-on. This is not the case in other countries; for example, in the UK, Allevenix is licensed for IV and intramuscular use,<ref name="NOAH1">{{cite web|title=Allevinix 50 mg/ml solution for injection for cattle, pigs and horses|url=http://www.noahcompendium.co.uk/?id=-453339|website=NOAH Compendium|publisher=National Office of National Health|access-date=19 April 2017}}</ref> and a pour-on product also exists.<ref name="NOAH2">{{cite web|title=Finadyne Transdermal 50 mg/ml pour-on solution for cattle|url=http://www.noahcompendium.co.uk/?id=-454763|website=NOAH Compendium|publisher=National Office of National Health|access-date=19 April 2017}}</ref>

In the US flunixin is not labelled for goat use, however, flunixin may be used in goats in an extra-label fashion under appropriate veterinary guidance. Flunixin administered subcutaneously to dairy goats may carry a milk withdraw recommendation of 36-60 hours.<ref name="pmid32509803">{{cite journal | vauthors = Smith JS, Marmulak TL, Angelos JA, Lin Z, Rowe JD, Carlson JL, Shelver WL, Lee EA, Tell LA | title = Pharmacokinetic Parameters and Estimated Milk Withdrawal Intervals for Domestic Goats (Capra Aegagrus Hircus) After Administration of Single and Multiple Intravenous and Subcutaneous Doses of Flunixin Meglumine | journal = Frontiers in Veterinary Science | volume = 7 | pages = 213 | date = 2020 | pmid = 32509803 | pmc = 7248982 | doi = 10.3389/fvets.2020.00213 | doi-access = free }}</ref> Interestingly, when given subcutaneously to goats in that study, tissue injury, such as seen in horses with intramuscular administration, was not observed.

==See also==
* [[Clonixin]]

==References==
{{Reflist}}

==External links==
* [http://www.ivis.org/products/product.asp?BID=639 Flunixin meglumine] {{Webarchive|url=https://web.archive.org/web/20070927031717/http://www.ivis.org/products/product.asp?BID=639 |date=2007-09-27 }}
* [http://www.wedgewoodpharmacy.com/monographs/flunixin.asp Flunixin Meglumine For Veterinary Use]
* [http://www.norbrook.com/products/flunixin-injection/ Flunixin licensing in the UK provided by Norbrook]

{{Anti-inflammatory products}}
{{Prostanoidergics}}

[[Category:Equine medications]]
[[Category:Nonsteroidal anti-inflammatory drugs]]
[[Category:Disubstituted pyridines]]
[[Category:Trifluoromethyl compounds]]
[[Category:Aromatic acids]]
[[Category:Merck & Co. people]]
[[Category:Anilines]]
[[Category:Alpha-Amino acids]]