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Ttrannn 11/sandbox
Clinical data
Trade namesComtan (single ingredient), Stalevo (multi-ingredient)
Other names
AHFS/Drugs.comMonograph
MedlinePlusa601236
License data
Pregnancy
category
  • AU: B3
Routes of
administration		Oral
ATC code
Legal status
Legal status
Pharmacokinetic data
Bioavailability35%
Protein binding98% (binds to serum albumin)
MetabolismHepatic
Elimination half-life0.4-0.7 hours
ExcretionFeces (90%), Urine (10%)
Identifiers
  • (2E)-2-cyano-3-(3,4-dihydroxy-5-nitrophenyl)-N,N-diethylprop-2-enamide
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
Chemical and physical data
FormulaC14H15N3O5
Molar mass305.286 g/mol g·mol−1
3D model (JSmol)
  • [O-][N+](=O)c1cc(\C=C(/C#N)C(=O)N(CC)CC)cc(O)c1O
  • InChI=1S/C14H15N3O5/c1-3-16(4-2)14(20)10(8-15)5-9-6-11(17(21)22)13(19)12(18)7-9/h5-7,18-19H,3-4H2,1-2H3/b10-5+ checkY
  • Key:JRURYQJSLYLRLN-BJMVGYQFSA-N checkY
  (verify)

Entacapone (INN) (/ˌɛntəkəˈpoʊn/ or /ɛnˈtækəpoʊn/) is a drug commonly used in combination with other medications for the treatment of Parkinson's disease.[1] It is known as a selective and reversible inhibitor of the catechol-O-methyltransferase (COMT) enzyme.[1] When taken together with levodopa (L-DOPA) and carbidopa, entacapone stops the catechol-O-methyltransferase enzyme from breaking down and metabolizing levodopa, resulting in an overall increase of levodopa remaining in the brain and body.[1]

Entacapone together with levodopa and carbidopa allows levodopa to have a longer effect in the brain and reduces Parkinson’s disease signs and symptoms for a greater length of time than levodopa and carbidopa therapy alone.[1]

Entacapone is developed by Orion Pharma and marketed by Novartis under the trade name Comtan.[1] Stalevo, another medication developed by Orion Pharma and marketed by Novartis, is a single tablet formulation that contains levodopa, carbidopa, and entacapone.[2]

Medical use[edit]

Entacapone is used as adjunct therapy with levodopa and carbidopa for people with Parkinson's disease to treat the signs and symptoms of end-of-dose “wearing-off."[3] “Wearing-off” is characterized by the re-appearance of both motor and non-motor symptoms of Parkinson’s disease occurring towards the end of a previous levodopa and carbidopa dose.[4]

Entacapone is an orally active drug that can be taken with or without food.[3][5]

A doctor’s prescription is required to use entacapone.[3] Potential limiting conditions to consider before starting entacapone include:[5]

Entacapone does not cure Parkinson’s disease.[5]

Adverse effects[edit]

The following adverse effects have been reported by people with Parkinson's disease treated with entacapone:

Dyskinesia[edit]

Entacapone may cause or worsen dyskinesia for people with Parkinson's disease treated together with levodopa and carbidopa.[1] In particular, “peak-dose dyskinesias” may occur when levodopa levels are at its peak concentration in the serum plasma.[6][7]

Sudden sleep onset[edit]

People have reported sudden sleep onset while engaging in daily activities without prior warning of drowsiness. In controlled studies, patients on entacapone had a 2.0% increased risk of somnolence compared to placebo.[1]

Orthostatic hypotension and syncope[edit]

Episodes of hypotension have been shown to be more common at the start of entacapone use.[1]

Hallucinations and psychotic-like behavior[edit]

Post-marketing data shows that entacapone may change or worsen mental status, leading to behaviors such as delusions, agitation, confusion, and delirium.[1]

Compulsive behavior[edit]

People using entacapone may experience increased urges to participate in gambling, sexual activities, money spending, and other stimulating reward behaviors.[1]

Diarrhea[edit]

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 weight loss, low potassium levels, and dehydration.[1] In clinical studies, severe diarrhea was the most common reason for discontinuation of entacapone.[8]

Urine discoloration[edit]

A common side-effect due to entacapone's metabolites which cause a person's urine to turn orange, red, brown, or black in color.[8]

Contraindications[edit]

There is a high risk for allergic reactions for people who are hypersensitive to entacapone.[1]

Mechanism of action[edit]

Entacapone is a selective and reversible inhibitor of catechol-O-methyltransferase (COMT).[1] COMT eliminates biologically active catechols present in catecholamines (dopamine, norepinephrine, and epinephrine) and their hydroxylated metabolites. When administered with a decarboxylase inhibitor, COMT acts as the major metabolizing enzyme for levodopa and metabolizes it to 3-methoxy-4-hydroxy-L-phenylalanine (3-OMD) in the brain and in the periphery.[1]

For the treatment of Parkinson’s disease, entacapone is given as an adjunct to levodopa and an aromatic amino acid decarboxylase inhibitor, carbidopa. Entacapone inhibits COMT and the metabolism of levodopa, thus increasing plasma levels of levodopa and causing more constant dopaminergic stimulation in order to reduce the signs and symptoms presented in the disease.[1]

Pharmacokinetics[edit]

Absorption[edit]

The transport maximum (Tmax) is approximately 1 hour. Absolute oral bioavailability (F) is 35.0%.[1]

Distribution[edit]

The volume of distribution (VD) after intravenous injection approximately 20.0 liters. Entacapone has high binding activity to serum albumin that limits its distribution into tissues.[1]

Metabolism and Elimination[edit]

Entacapone has a half-life of approximately 0.3-0.7 hours.[1] It is primarily metabolized by the liver with 0.2% of the medication unchanged in urine.[1]

Special populations[edit]

Pregnancy and Breastfeeding[edit]

Pregnancy Category C: risk is not ruled out.[1]

Although there have been animal studies that showed that entacapone was excreted into maternal rat milk, there have been no studies with human breast milk. Mothers should speak with their physician before using entacapone while breastfeeding or during pregnancy.[1]

Pediatrics[edit]

Entacapone safety and efficacy have not been assessed in infants or children.[1]

Liver Impairment[edit]

Biliary excretion is the major route of excretion for entacapone. Entacapone may require additional caution when given to people with liver dysfunction.[1]

Kidney Impairment

No clinically significant considerations for people with poor kidney function.[1]

References[edit]

  1. ^ a b c d e f g h i j k l m n o p q r s t u v w x "Comtan Full Prescribing Information-Novartis" (PDF). Pharma.us.novartis.com. July 2014. Retrieved 4 November 2015.
  2. ^ "Stalevo Prescribing Information" (PDF). Novartis. Novartis Pharmaceuticals. Retrieved 4 November 2015.
  3. ^ a b c "PubMedHealth". PubMedHealth. 1 October 2015. Retrieved 4 November 2015.
  4. ^ Pahwa, R (April 2009). "Levodopa-related wearing-off in Parkinson's disease: Identification and Management". Current Medical Research and Opinion. PMID 19228103. {{cite journal}}: |access-date= requires |url= (help)
  5. ^ a b c "Entacapone". Medlineplus - NIH. American Society of Health-System Pharmacist. September 2010. Retrieved 4 November 2015.
  6. ^ "Late (complicated) Parkinson's Disease". National Guideline Clearing House. November 2006. Retrieved 3 November 2015.
  7. ^ Salat, David (1 January 2013). "Levodopa in the Treatment of Parkinson's Disease: Current Status and New Developments". Journal of Parkinson's Disease. PMID 23948989. {{cite journal}}: |access-date= requires |url= (help)
  8. ^ a b Koda-Kimble, Mary Anne (2013). Koda-Kimble & Young's Applied Therapeutics: The Clinical Use of Drugs. Philidelphia: Lippincott Williams & Wilkins. pp. 1373–1374. ISBN 978-1609137137.

External links[edit]


Category:COMT inhibitors Category:Catechols Category:Nitrobenzenes Category:Nitriles Category:Amides

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