Wikipedia:WikiProject Chemicals/Chembox validation/VerifiedDataSandbox and Entacapone: Difference between pages

{{Short description|Chemical compound}}

{{Use dmy dates|date=March 2024}}

| verifiedrevid = 477167001

| image = Entacapone.svg

| alt = Skeletal formula

| image2 = Entacapone molecule spacefill.png

| alt2 = Space-filling model of entacapone

| pronounce = {{IPAc-en|ˌ|ɛ|n|t|ə|k|ə|ˈ|p|oʊ|n}} or {{IPAc-en|ɛ|n|ˈ|t|æ|k|ə|p|oʊ|n}}

| tradename = Comtan (single ingredient), Stalevo (multi-ingredient)

| DailyMedID = Entacapone

| pregnancy_AU = B3

| licence_EU = yes

| legal_AU = S4

| legal_BR = C1

| legal_BR_comment = <ref>{{Cite web |author=Anvisa |author-link=Brazilian Health Regulatory Agency |date=31 March 2023 |title=RDC Nº 784 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial |trans-title=Collegiate Board Resolution No. 784 - Lists of Narcotic, Psychotropic, Precursor, and Other Substances under Special Control|url=https://www.in.gov.br/en/web/dou/-/resolucao-rdc-n-784-de-31-de-marco-de-2023-474904992 |url-status=live |archive-url=https://web.archive.org/web/20230803143925/https://www.in.gov.br/en/web/dou/-/resolucao-rdc-n-784-de-31-de-marco-de-2023-474904992 |archive-date=3 August 2023 |access-date=16 August 2023 |publisher=[[Diário Oficial da União]] |language=pt-BR |publication-date=4 April 2023}}</ref>

| legal_CA = Rx-only

| legal_UK = POM

| legal_US = Rx-only

| legal_EU = Rx-only

| routes_of_administration = [[Oral administration|By mouth]]

| ATC_prefix = N04

| ATC_suffix = BX02

| ATC_supplemental =

| elimination_half-life = 0.4–0.7 hours

| excretion = Feces (90%), urine (10%)

| IUPHAR_ligand = 6647

| DrugBank_Ref = {{drugbankcite|correct|drugbank}}

| synonyms =

| IUPAC_name = (2''E'')-2-Cyano-3-(3,4-dihydroxy-5-nitrophenyl)-''N'',''N''-diethylprop-2-enamide

| C=14 | H=15 | N=3 | O=5

<!-- FAIR USE of Comtan.png: see image description page at http://en.wikipedia.org/wiki/Image:Comtan.png for rationale -->

'''Entacapone''', sold under the brand name '''Comtan''' among others, is a medication commonly used in combination with other medications for the treatment of [[Parkinson's disease]].<ref name=":02">{{Cite web|url = https://www.pharma.us.novartis.com/product/pi/pdf/comtan.pdf|title = Comtan Full Prescribing Information-Novartis|date = July 2014|access-date = 4 November 2015|website = Pharma.us.novartis.com|archive-date = 15 March 2016|archive-url = https://web.archive.org/web/20160315172434/http://www.pharma.us.novartis.com/product/pi/pdf/comtan.pdf|url-status = dead}}</ref> Entacapone together with [[levodopa]] and [[carbidopa]] allows levodopa to have a longer effect in the brain and reduces Parkinson's disease [[Parkinson's disease#Signs and symptoms|signs and symptoms]] for a greater length of time than levodopa and carbidopa therapy alone.<ref name=":02" />

Entacapone is a [[binding selectivity|selective]] and [[reversible inhibitor]] of the [[enzyme]] [[catechol-O-methyl transferase|catechol-''O''-methyltransferase]] (COMT).<ref name=":02" /> When taken together with levodopa (<small>L</small>-DOPA) and carbidopa, entacapone stops COMT from [[metabolism|breaking down]] levodopa, resulting in an overall increase of levodopa remaining in the brain and body.<ref name=":02" /> Entacapone [[peripherally selective drug|does not cross into the brain]] and hence does not inhibit COMT there.<ref name="Habet2022">{{cite journal | vauthors = Habet S | title = Clinical Pharmacology of Entacapone (Comtan) From the FDA Reviewer | journal = Int J Neuropsychopharmacol | volume = 25 | issue = 7 | pages = 567–575 | date = August 2022 | pmid = 35302623 | pmc = 9352175 | doi = 10.1093/ijnp/pyac021 | url = | quote = Entacapone is a potent and specific peripheral catechol-O-methyltransferase inhibitor. [...] Entacapone has no antiparkinsonian activity as a sole agent. Therefore, it must be given as an adjunct to LD and a peripherally acting DDC inhibitor, such as carbidopa. Entacapone acts peripherally and does not penetrate the blood-brain barrier (BBB). [...] It is poorly lipophilic and does not penetrate the BBB to any significant extent. Its clinical effects are thus due to peripheral COMT inhibition only (Nutt, 1998; Fahn et al, 2004). [...] Entacapone is poorly lipophilic. Therefore, its clinical effects are due to peripheral COMT inhibition alone. [...] Entacapone is a potent, specific, and reversible COMT inhibitor. The drug has been shown to act peripherally, but not centrally, when given at clinically effective doses.}}</ref>

[[Carbidopa/levodopa/entacapone]] (Stalevo), a medication developed by [[Orion Pharma]] and marketed by [[Novartis]], is a single tablet [[Formulation#Pharmacy|formulation]] that contains levodopa, carbidopa, and entacapone.<ref>{{cite web | title=Stalevo- carbidopa, levodopa, and entacapone tablet, film coated | website=DailyMed | date=7 January 2020 | url=https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=5edfc3e7-f80d-47ee-897a-c02ff4eb3e74 | access-date=14 March 2020}}</ref>

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== Medical uses ==

Entacapone is used [[Adjunct therapy|in addition to]] levodopa and carbidopa for people with Parkinson's disease to treat the signs and symptoms of end-of-dose "wearing-off."<ref name=":3" /> "Wearing-off" is characterized by the re-appearance of both [[Parkinson's disease#Motor|motor]] and [[Parkinson's disease#Neuropsychiatric|non-motor]] symptoms of Parkinson's disease occurring towards the end of a previous levodopa and carbidopa dose.<ref name=":0">{{cite journal | vauthors = Pahwa R, Lyons KE | title = Levodopa-related wearing-off in Parkinson's disease: identification and management | journal = Current Medical Research and Opinion | volume = 25 | issue = 4 | pages = 841–9 | date = April 2009 | pmid = 19228103 | doi = 10.1185/03007990902779319 | s2cid = 71616140 }}<!--|access-date = 3 November 2015--></ref> In clinical trials, entacapone has not been shown to slow progression or reverse Parkinson's disease.<ref name=":02" /><ref name=":0" /><ref name=":2" />

Entacapone is an [[Pharmaceutical formulation#Enteral formulations|orally active drug]] that can be taken with or without food.<ref name=":3">{{Cite web|url = https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0044789/?report=details|title = PubMedHealth|date = 1 October 2015|access-date = 4 November 2015|website = PubMedHealth}}</ref><ref name=":2">{{Cite web|url = https://www.nlm.nih.gov/medlineplus/druginfo/meds/a601236.html|title = Entacapone|date = September 2010|access-date = 4 November 2015|website = Medlineplus - NIH|publisher = American Society of Health-System Pharmacist}}</ref>

=== Pregnancy and breastfeeding ===

[[Pregnancy category|Pregnancy category C]]: risk is not ruled out.<ref name=":02" />

Although there have been animal studies that showed that entacapone was [[excreted]] into maternal rat milk, there have been no studies with [[Breast milk|human breast milk]]. Caution is advised for mothers taking entacapone while breastfeeding or during pregnancy.<ref name=":02" />

=== Children ===

Entacapone safety and efficacy have not been assessed in [[infant]]s or children.<ref name=":02" />

=== Liver problems ===

[[Bile duct|Biliary]] excretion is the major route of [[excretion]] for entacapone. People with liver dysfunction may require additional caution and more frequent liver function monitoring while taking entacapone.<ref name=":02" />

===Kidney problems===

There are no significant considerations for people with poor kidney function taking entacapone.<ref name=":02" />

== Contraindications ==

There is a high risk for allergic reactions for people who are hypersensitive to entacapone.<ref name=":02" />

Potential limiting conditions to consider before starting entacapone include:<ref name=":2" />

* History of [[allergic reaction]] to entacapone

* History of [[liver disease]], [[liver dysfunction]], or [[alcoholism]]

* Current or planned [[pregnancy]]

* Current or planned [[Surgery|surgeries]]

== Side effects ==

The following [[Adverse effects|side effects]] have been reported by people with Parkinson's disease treated with entacapone:

* Abdominal pain

* Nausea

* Vomiting

* Fatigue

* Dry mouth

* Back ache

=== Movement problems ===

The most common side effect of entacapone is movement problems, which occur in 25% of people taking entacapone.<ref name=":02" /> This drug may cause or worsen [[dyskinesia]] for people with Parkinson's disease treated together with levodopa and carbidopa.<ref name=":02" /> In particular, "[[Levodopa-induced dyskinesia|peak-dose dyskinesias]]" may occur when levodopa levels are at its [[Cmax (pharmacology)|peak concentration]] in the [[Blood plasma|serum plasma]].<ref>{{Cite web|url = http://www.guideline.gov/content.aspx?id=34900&search=parkinson%27s+disease|title = Late (complicated) Parkinson's Disease|date = November 2006|access-date = 3 November 2015|website = National Guideline Clearing House|archive-url = https://web.archive.org/web/20151024200646/http://www.guideline.gov/content.aspx?id=34900|archive-date = 24 October 2015|url-status = dead|df = dmy-all}}</ref><ref>{{cite journal | vauthors = Salat D, Tolosa E | title = Levodopa in the treatment of Parkinson's disease: current status and new developments | journal = Journal of Parkinson's Disease | volume = 3 | issue = 3 | pages = 255–69 | date = January 2013 | pmid = 23948989 | doi = 10.3233/JPD-130186 | doi-access = free }}<!--|access-date = 3 November 2015--></ref>

=== Diarrhea ===

10% of patients taking entacapone have been shown to experience [[diarrhea]].<ref name=":02" /> Diarrhea may occur within 4–12 weeks of initial entacapone use but resolves after discontinuation of the drug. Use of entacapone in the presence of diarrhea can also be associated with [[Dieting#How the body eliminates fat|weight loss]], low [[potassium]] levels, and [[dehydration]].<ref name=":02" /> In clinical studies, severe diarrhea was the most common reason for discontinuation of entacapone.<ref name=":1">{{Cite book|title = Koda-Kimble & Young's Applied Therapeutics: The Clinical Use of Drugs|last = Koda-Kimble|first = Mary Anne | name-list-style = vanc |publisher = Lippincott Williams & Wilkins|year = 2013|isbn = 978-1609137137|location = Philadelphia|pages = 1373–1374}}</ref>

=== Urine color ===

10% of people taking entacapone experience a change in urine color to orange, red, brown, or black. This side effect is due to entacapone metabolism and excretion in the urine and shown to not be harmful.<ref name=":1" />

=== Sudden sleep onset ===

People have reported [[Sleep onset|sudden sleep onset]] while engaging in daily activities without prior warning of drowsiness. In controlled studies, patients on entacapone had a 2% increased risk of [[somnolence]] compared to [[placebo]].<ref name=":02" />

=== Low blood pressure ===

Episodes of [[orthostatic hypotension]] have been shown to be more common at the start of entacapone use due to increased levels of levodopa.<ref name=":02" />

=== Behavior problems===

[[Postmarketing surveillance|Post-marketing data]] shows that entacapone may change or worsen [[Mental status changes|mental status]], leading to behaviors such as [[delusion]]s, agitation, confusion, and [[delirium]].<ref name=":02" />

People taking entacapone may experience increased urges to participate in gambling, sexual activities, money spending, and other stimulating reward behaviors.<ref name=":02" />

== Interactions ==

In studies, entacapone has shown a low potential for interaction with other drugs. In theory, it could interact with [[MAO inhibitor]]s, [[tricyclic antidepressant]]s and [[noradrenaline reuptake inhibitor]]s because they also increase [[catecholamine]] levels in the body, with drugs being metabolized by COMT (for example [[methyldopa]], [[dobutamine]], [[apomorphine]], [[adrenaline]], and [[isoprenaline]]), with iron because it could form [[chelate]]s, with substances binding to the same [[albumin]] site in the blood plasma (for example [[diazepam]] and [[ibuprofen]]), and with drugs being metabolized by the liver enzyme [[CYP2C9]] (for example [[warfarin]]). None of the medications tested in studies have shown clinically relevant interactions, except perhaps warfarin for which a 13% ([[confidence interval|CI₉₀]]: 6–19%) increase in [[International normalized ratio|INR]] was seen when combined with entacapone.<ref name="EMA" />

== Pharmacology ==

===Mechanism of action===

Entacapone is a selective and reversible [[COMT inhibitor|inhibitor of catechol-''O''-methyltransferase]] (COMT).<ref name=":02" /> COMT eliminates biologically active [[catechol]]s present in [[catecholamine]]s ([[dopamine]], [[norepinephrine]], and [[epinephrine]]) and their [[Hydroxylation|hydroxylated]] [[metabolite]]s. When administered with a [[decarboxylase inhibitor]], COMT acts as the major metabolizing enzyme for levodopa and metabolizes it to [[3-O-Methyldopa|3-methoxy-4-hydroxy-<small>L</small>-phenylalanine]] (3-OMD) in the brain and in the [[Peripheral vascular system|periphery]].<ref name=":02" />

For the treatment of Parkinson's disease, entacapone is given as an adjunct to levodopa and an aromatic amino acid decarboxylase inhibitor, [[carbidopa]]. Entacapone is [[peripherally selective drug|peripherally selective]] and inhibits COMT in the body but not in the brain.<ref name="Habet2022" /><ref name="Arzneistoff-Profile">{{cite book|title=Arzneistoff-Profile| veditors = Dinnendahl V, Fricke U |publisher=Govi Pharmazeutischer Verlag|location=Eschborn, Germany|date=2000|edition=16|volume=4|isbn=978-3-7741-9846-3|language=de}}</ref> As a result, entacapone inhibits the peripheral metabolism of levodopa, thus increasing plasma levels of levodopa.<ref name="Habet2022" /><ref name=":02" /> This causes more constant dopaminergic stimulation in order to reduce the [[Signs and symptoms of Parkinson's disease|signs and symptoms]] presented in the disease.<ref name=":02" />

=== Pharmacokinetics ===

==== Absorption ====

The time to highest blood plasma concentrations is approximately one hour. The substance undergoes extensive [[first-pass metabolism]]. Absolute oral [[bioavailability]] (''F'') is 35%.<ref name=":02" /><ref name="EMA">{{cite web|url=http://www.ema.europa.eu/docs/en_GB/document_library/EPAR_-_Product_Information/human/000171/WC500033079.pdf|title=Comtan: EPAR – Product Information|publisher=[[European Medicines Agency]]|date=10 March 2015|access-date=17 April 2017|archive-date=16 March 2018|archive-url=https://web.archive.org/web/20180316165631/http://www.ema.europa.eu/docs/en_GB/document_library/EPAR_-_Product_Information/human/000171/WC500033079.pdf|url-status=dead}}</ref>

==== Distribution ====

The [[volume of distribution]] (V_d) after [[intravenous injection]] is approximately 20 liters. 98% of the circulating entacapone is bound to serum [[Human serum albumin|albumin]], which limits its [[Distribution (pharmacology)|distribution]] into [[Tissue (biology)|tissues]].<ref name=":02" /><ref name="EMA" /> Entacapone has low [[lipophilicity]] and does not significantly cross the [[blood–brain barrier]].<ref name="Habet2022" /> As a result, it is a [[peripherally selective drug]] and does not act in the [[brain]].<ref name="Habet2022" />

==== Metabolism and elimination ====

Entacapone is primarily metabolized to its [[glucuronide]] in the liver, and 5% are converted into the [[E-Z notation|''Z''-isomer]].<ref name="EMA" /> It has a [[Biological half-life|half-life]] of approximately 0.3–0.7 hours, with only 0.2% being excreted unchanged in the urine.<ref name=":02" />

==Research==

===Restless legs syndrome===

Entacapone, in conjunction with [[carbidopa/levodopa|levodopa and carbidopa]], was under development for use in the treatment of [[restless legs syndrome]] (RLS), but development was discontinued.<ref name="AdisInsight">{{cite web | title=Entacapone - Novartis/Orion - Novartis/Orion | website=AdisInsight | date=5 November 2023 | url=https://adisinsight.springer.com/drugs/800002646 | access-date=10 July 2024}}</ref><ref name="FuldaWetter2005">{{cite journal | vauthors = Fulda S, Wetter TC | title = Emerging drugs for restless legs syndrome | journal = Expert Opin Emerg Drugs | volume = 10 | issue = 3 | pages = 537–552 | date = August 2005 | pmid = 16083328 | doi = 10.1517/14728214.10.3.537 | url = }}</ref>

== References ==

{{Reflist}}

{{Antiparkinson}}

{{Monoamine metabolism modulators}}

{{Portal bar | Medicine}}

[[Category:Antiparkinsonian agents]]

[[Category:Carboxamides]]

[[Category:Catechols]]

[[Category:Catechol-O-methyltransferase inhibitors]]

[[Category:Drugs developed by Novartis]]

[[Category:Nitriles]]

[[Category:Nitrophenol derivatives]]

[[Category:Peripherally selective drugs]]