Flupirtine Explained
Flupirtine is an aminopyridine that functions as a centrally acting non-opioid analgesic that was originally used as an analgesic for acute and chronic pain[1] but in 2013 due to issues with liver toxicity, the European Medicines Agency restricted its use to acute pain, for no more than two weeks, and only for people who cannot use other painkillers.[2] In March 2018, marketing authorisations for flupirtine were withdrawn following a European Medicines Agency recommendation based on the finding that the restrictions introduced in 2013 had not been sufficiently followed in clinical practice, and cases of serious liver injury still occurred including liver failure.[3]
Flupirtine is a selective neuronal potassium channel opener (SNEPCO) that also has NMDA receptor antagonist and GABAA modulatory properties.[4]
It first became available in Europe in 1984 under the brand name Katadolon and after it went off patent many generic brands were introduced.
Uses
Flupirtine is used as an analgesic for acute pain, in moderate-to-severe cases.[1] [5] Its muscle relaxant properties make it popular for back pain and other orthopaedic uses, but it is also used for migraines, in oncology, postoperative care, and gynaecology.
In 2013 due to issues with liver toxicity, the European Medicines Agency restricted its use to acute pain, for no more than two weeks, and only for people who cannot use other painkillers.[2]
Side effects
The most serious side effect is frequent hepatotoxicity which prompted regulatory agencies to issue several warnings and restrictions.[6] [7]
Flupirtine is devoid of negative psychological or motor function effects, or effects on reproductive function.[8] [9]
Abuse and dependence
Although some studies have reported flupirtine has no addictive properties,[10] [11] there was suggestion that it may possess some abuse potential and liability.[12] There were at least two registered cases of flupirtine abuse.[13] Drug tolerance does not develop in most cases, but has individually occurred.
Mechanism of action
Flupirtine is a selective neuronal potassium channel opener that also has indirect NMDA receptor antagonist and GABAA receptor modulatory properties.[4] [1]
History
Flupirtine was discovered and developed between the 1970s and the 1990s by Chemiewerk Homburg in Frankfurt am Main, Germany, which became Degussa Pharma Group and then through mergers, ASTA Pharma and Asta Medica.[4] Retigabine, in which the pyridine group in flupirtine is replaced with a phenyl group, was discovered as part of the same program and has a similar mechanism of action.[4]
It was approved for the treatment of pain in 1984 in Europe under the brand name Katadolon.[14]
As of 2013 it was used in 11 member countries: Bulgaria, Estonia, Germany, Hungary, Italy, Latvia, Lithuania, Poland, Portugal, Romania and Slovak Republic.[15] Many generics entered the European market around 2011.[16]
It was never introduced to the United States market for any indication but in 2008, Adeona Pharmaceuticals, Inc. (now called Synthetic Biologics, Inc.) obtained an option to license issued and patent pending applications relating to flupirtine's use in the treatment of ophthalmic indications, particularly retinitis pigmentosa.[17]
In 2010 retigabine was approved by the FDA as an anticonvulsant for the treatment of refractory partial-onset seizures in treatment-experienced patients.[18]
As of 2016 it is marketed under many brand names, including Efiret, Flupigil, Flupirtin, Flupirtina, Flupirtine, Flupizen, Fluproxy, Katadolon, Metanor, Trancolong, and Zentiva.[19]
Research
Flupirtine has been noted for its neuroprotective properties, and has been investigated for possible use in Creutzfeldt–Jakob disease, Alzheimer's disease, and multiple sclerosis.[20] [21] It has also been proposed as a possible treatment for Batten disease.[22]
Flupirtine underwent a clinical trial as a treatment for multiple sclerosis[23] and fibromyalgia.[24] Flupirtine showed promise for fibromyalgia due to its different action than the three approved by U.S. FDA drugs: pregabalin, milnacipran, and duloxetine.[25] Additionally, there are case reports regarding flupirtine as a treatment for fibromyalgia.[26] Adeona Pharmaceuticals (now called Synthetic Biologics) sub-licensed its patents for using flupirtine for fibromyalgia to Meda AB in May 2010.
Notes and References
- Harish S, Bhuvana K, Bengalorkar GM, Kumar T . Flupirtine: Clinical pharmacology . Journal of Anaesthesiology Clinical Pharmacology . 28 . 2 . 172–177 . April 2012 . 22557738 . 3339720 . 10.4103/0970-9185.94833 . free .
- Web site: Flupirtine-containing medicines. European Medicines Agency. November 21, 2013.
- Web site: European Medicines Agency - Human medicines - Flupirtine-containing medicinal products. www.ema.europa.eu. en. 2018-03-18. 2022-01-21. https://web.archive.org/web/20220121013335/http://www.ema.europa.eu/ema/index.jsp?curl=pages/medicines/human/referrals/Flupirtine-containing_medicinal_products/human_referral_prac_000069.jsp&mid=WC0b01ac05805c516f. dead.
- Szelenyi I . Flupirtine, a re-discovered drug, revisited . Inflammation Research . 62 . 3 . 251–258 . March 2013 . 23322112 . 10.1007/s00011-013-0592-5 . 16535456 .
- McMahon FG, Arndt WF, Newton JJ, Montgomery PA, Perhach JL . Clinical experience with flupirtine in the U.S . Postgraduate Medical Journal . 63 Suppl 3 . 3 . 81–85 . 1987 . 3328854 .
- http://www.ema.europa.eu/ema/index.jsp?curl=pages/medicines/human/referrals/Flupirtine-containing_medicines/human_referral_prac_000019.jsp&mid=WC0b01ac05805c516f EMA information about flupirtine
- Web site: Flupirtin: EMA startet Risikobewertung wegen Leberrisiko . . 15 March 2013 .
- Singal R, Gupta P, Jain N, Gupta S . Role of flupirtine in the treatment of pain - chemistry and its effects . Maedica . 7 . 2 . 163–166 . June 2012 . 23401726 . 3557425 .
- Web site: DRUGDEX Evaluations - Flupirtine. 24 March 2013.
- Preston KL, Funderburk FR, Liebson IA, Bigelow GE . Evaluation of the abuse potential of the novel analgesic flupirtine maleate . Drug and Alcohol Dependence . 27 . 2 . 101–113 . March 1991 . 2055157 . 10.1016/0376-8716(91)90027-v .
- Sofia RD, Diamantis W, Gordon R . Abuse potential and physical dependence liability studies with flupirtine maleate in laboratory animals . Postgraduate Medical Journal . 63 . 35–40 . 1987 . Suppl 3 . 3447127 .
- Gahr M, Freudenmann RW, Connemann BJ, Hiemke C, Schönfeldt-Lecuona C . Abuse liability of flupirtine revisited: implications of spontaneous reports of adverse drug reactions . Journal of Clinical Pharmacology . 53 . 12 . 1328–1333 . December 2013 . 24037995 . 10.1002/jcph.164 . 35299692 .
- Stoessel C, Heberlein A, Hillemacher T, Bleich S, Kornhuber J . Positive reinforcing effects of flupirtine--two case reports . Progress in Neuro-Psychopharmacology & Biological Psychiatry . 34 . 6 . 1120–1121 . August 2010 . 20362025 . 10.1016/j.pnpbp.2010.03.031 . 19710997 .
- Book: Allen RC . Hesp B . Annual Reports in Medicinal Chemistry, Volume 21. 1986. Academic Press. Orlando. 9780080583655. 328. https://books.google.com/books?id=qsFCGskRHZQC&pg=PA328. To Market, To Market - 1985.
- Web site: Assessment report for flupirtine containing medicinal products. EMA. June 24, 2013.
- Web site: Rationale for the triggering of procedure under Article 107i of Directive 2001/83/EC on flupirtine presented by the Federal Institute for Drugs and Medicinal Devices/BfArM, Germany. EMA. March 8, 2013.
- Web site: Adeona Pharmaceuticals and National Neurovision Research Institute (NNRI) Collaborate to Test Flupirtine for Retinitis Pigmentosa. Synthetic Biologics, Inc.. 2 June 2014. Ann Arbor, MI and Owings Mills, MD. December 2, 2008. https://web.archive.org/web/20140606203650/http://www.syntheticbiologics.com/index.php?s=43&item=38. 6 June 2014. dead.
- Web site: POTIGA (ezogabine) Tablets, CV. Full Prescribing Information Revised: September, 2013. Initial U.S. Approval: 2011.. GlaxoSmithKline and Valeant Pharmaceuticals. 2 June 2014.
- https://www.drugs.com/international/flupirtine.html Flupirtine
- Klawe C, Maschke M . Flupirtine: pharmacology and clinical applications of a nonopioid analgesic and potentially neuroprotective compound . Expert Opinion on Pharmacotherapy . 10 . 9 . 1495–1500 . June 2009 . 19505216 . 10.1517/14656560902988528 . 11597721 .
- Swedberg MD, Shannon HE, Nickel B, Goldberg SR . Pharmacological mechanisms of action of flupirtine: a novel, centrally acting, nonopioid analgesic evaluated by its discriminative effects in the rat . The Journal of Pharmacology and Experimental Therapeutics . 246 . 3 . 1067–1074 . September 1988 . 2901483 .
- Dhar S, Bitting RL, Rylova SN, Jansen PJ, Lockhart E, Koeberl DD, Amalfitano A, Boustany RM . 6 . Flupirtine blocks apoptosis in batten patient lymphoblasts and in human postmitotic CLN3- and CLN2-deficient neurons . Annals of Neurology . 51 . 4 . 448–466 . April 2002 . 11921051 . 10.1002/ana.10143 . 23653281 .
- http://clinicaltrials.gov/ct2/show/NCT00623415 Flupirtine as Oral Treatment in Multiple Sclerosis (FLORIMS)
- http://www.biospace.com/news_story.aspx?NewsEntityId=93287 Pipex Pharmaceuticals (PPXP)' Oral Flupirtine Receives IND With FDA for Phase II Clinical Trial for Fibromyalgia
- Web site: Partnered Program. Effirma for Fibromyalgia. Synthetic Biologics, Inc.. 2 June 2014. https://web.archive.org/web/20140606210655/http://www.syntheticbiologics.com/fibromyalgia. 6 June 2014. dead.
- Stoll AL, Belmont MA. (2000) "Fibromyalgia Symptoms Relieved by Flupirtine: An Open-Label Case Series " Psychosomatics 41:371-372. Accessed 20 September 2011.