Tolcapone

Tolcapone


Systematic (IUPAC) name
(3,4-dihydroxy-5-nitrophenyl)(4-methylphenyl)methanone
Clinical data
Trade names	Tasmar
AHFS/Drugs.com	monograph
MedlinePlus	a698036
Pregnancy cat.	C(US)
Legal status	℞-only (US)
Routes	Oral
Pharmacokinetic data
Bioavailability	65%
Protein binding	>99.9%
Half-life	2-3.5 hours
Identifiers
CAS number	134308-13-7^Y
ATC code	N04BX01
PubChem	CID 4659569
DrugBank	APRD00445
ChemSpider	3848682^Y
UNII	CIF6334OLY^Y
KEGG	D00786^Y
ChEMBL	CHEMBL1324^Y
Chemical data
Formula	C₁₄H₁₁N O₅
Mol. mass	273.241 g/mol
SMILES	eMolecules & PubChem
InChI InChI=1S/C14H11NO5/c1-8-2-4-9(5-3-8)13(17)10-6-11(15(19)20)14(18)12(16)7-10/h2-7,16,18H,1H3^Y Key:MIQPIUSUKVNLNT-UHFFFAOYSA-N^Y
N(what is this?) (verify)

Tolcapone (tradename Tasmar) is a drug that inhibits the enzyme catechol-O-methyl transferase (COMT). ^[1]

1 Uses
2 Chemistry
3 Pharmacology
4 See also
5 References

Uses

Tolcapone is used in the treatment of Parkinson's disease as an adjunct to levodopa/carbidopa medication.

Chemistry

Tolcapone is a yellow, odorless, non-hygroscopic, crystalline compound with a relative molecular mass of 273.25. The chemical name of tolcapone is 3,4-dihydroxy-4’-methyl-5-nitrobenzophenone. Its empirical formula is C₁₄H₁₁NO₅.

Pharmacology

Tolcapone has the ability to cross the blood-brain barrier and thus exerts its COMT inhibitory effects in the CNS as well as in the periphery.

Tolcapone has demonstrated significant hepatotoxicity^[2] that limits the drug's utility. Entacapone, another COMT inhibitor, is an alternative selection for L-DOPA adjunct therapy in the treatment of Parkinson's disease, largely since it has a more favorable toxicity profile.

Normally, administration of levodopa is compromised when COMT converts it to 3-methoxy-dopa. By preventing this effect, more of the levodopa that is administered reaches the CNS. Additionally, levodopa that is in the CNS, after being converted to dopamine, will not be degraded by COMT when tolcapone inhibits COMT activity.

References

^ Antonini A, Abbruzzese G, Barone P, et al. (February 2008). "COMT inhibition with tolcapone in the treatment algorithm of patients with Parkinson's disease (PD): relevance for motor and non-motor features". Neuropsychiatric disease and treatment 4 (1): 1–9. PMC 2515921. PMID 18728767. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2515921.
^ Olanow CW, Watkins PB (2007). "Tolcapone: an efficacy and safety review (2007)". Clinical neuropharmacology 30 (5): 287–94. doi:10.1097/wnf.0b013e318038d2b6. PMID 17909307. http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?an=00002826-200709000-00006.

Antiparkinson agents (N04)

Dopaminergics

DA precursors/prodrugs	Etilevodopa • Droxidopa • Levodopa^# • Melevodopa

DA receptor agonists	Aplindore • Apomorphine • Bromocriptine • Cabergoline • Ciladopa • Dihydroergocryptine • Lisuride • Pardoprunox • Pergolide • Piribedil • Pramipexole • Ropinirole • Rotigotine

MAO-B inhibitors	Ladostigil • Lazabemide • Mofegiline • Pargyline • Rasagiline • Selegiline

COMT inhibitors	Entacapone • Tolcapone

Aromatic L-amino acid decarboxylase inhibitors	Benserazide • Carbidopa^# • Methyldopa

Anticholinergics

Benzatropine • Biperiden^# • Bornaprine • Chlorphenoxamine • Cyrimine • Dexetimide • Dimenhydrinate • Diphenhydramine • Etanautine • Etybenzatropine • Mazaticol • Metixene • Orphenadrine • Phenglutarimide • Piroheptine • Procyclidine • Profenamine • Trihexyphenidyl • Tropatepine

Others

Amantadine • Budipine • Memantine • Rimantadine

^#WHO-EM. ^‡Withdrawn from market. Clinical trials: ^†Phase III. ^§Never to phase III

M: CNS

anat(n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp

noco(m/d/e/h/v/s)/cong/tumr, sysi/epon, injr

proc, drug(N1A/2AB/C/3/4/7A/B/C/D)

Dopaminergics

Receptor ligands

Agonists	Adamantanes: Amantadine • Memantine • Rimantadine; Aminotetralins: 7-OH-DPAT • 8-OH-PBZI • Rotigotine • UH-232; Benzazepines: 6-Br-APB • Fenoldopam • SKF-38,393 • SKF-77,434 • SKF-81,297 • SKF-82,958 • SKF-83,959; Ergolines: Bromocriptine • Cabergoline • Dihydroergocryptine • Lisuride • LSD • Pergolide; Dihydrexidine derivatives: 2-OH-NPA • A-86,929 • Ciladopa • Dihydrexidine • Dinapsoline • Dinoxyline • Doxanthrine; Others: A-68,930 • A-77636 • A-412,997 • ABT-670 • ABT-724 • Aplindore • Apomorphine • Aripiprazole • Bifeprunox • BP-897 • CY-208,243 • Dizocilpine • Etilevodopa • Flibanserin • Ketamine • Melevodopa • Modafinil • Pardoprunox • Phencyclidine • PD-128,907 • PD-168,077 • PF-219,061 • Piribedil • Pramipexole • Propylnorapomorphine • Pukateine • Quinagolide • Quinelorane • Quinpirole • RDS-127 • Ro10-5824 • Ropinirole • Rotigotine • Roxindole • Salvinorin A • SKF-89,145 • Sumanirole • Terguride • Umespirone • WAY-100,635

Antagonists	Typical antipsychotics: Acepromazine • Azaperone • Benperidol • Bromperidol • Clopenthixol • Chlorpromazine • Chlorprothixene • Droperidol • Flupentixol • Fluphenazine • Fluspirilene • Haloperidol • Loxapine • Mesoridazine • Methotrimeprazine • Nemonapride • Penfluridol • Perazine • Periciazine • Perphenazine • Pimozide • Prochlorperazine • Promazine • Sulforidazine • Sulpiride • Sultopride • Thioridazine • Thiothixene • Trifluoperazine • Triflupromazine • Trifluperidol • Zuclopenthixol; Atypical antipsychotics: Amisulpride • Asenapine • Blonanserin • Cariprazine • Carpipramine • Clocapramine • Clorotepine • Clozapine • Gevotroline • Iloperidone • Lurasidone • Melperone • Molindone • Mosapramine • Olanzapine • Paliperidone • Perospirone • Piquindone • Quetiapine • Remoxipride • Risperidone • Sertindole • Tiospirone • Ziprasidone • Zotepine; Antiemetics: AS-8112 • Alizapride • Bromopride • Clebopride • Domperidone • Metoclopramide • Thiethylperazine; Others: Amoxapine • Buspirone • Butaclamol • Ecopipam • EEDQ • Eticlopride • Fananserin • L-745,870 • Nafadotride • Nuciferine • PNU-99,194 • Raclopride • Sarizotan • SB-277,011-A • SCH-23,390 • SKF-83,959 • Sonepiprazole • Spiperone • Spiroxatrine • Stepholidine • Tetrahydropalmatine • Tiapride • UH-232 • Yohimbine

Reuptake inhibitors

Plasmalemmal

DAT inhibitors

Piperazines: DBL-583 • GBR-12,935 • Nefazodone • Vanoxerine; Piperidines: BTCP • Desoxypipradrol • Dextromethylphenidate • Difemetorex • Ethylphenidate • Methylnaphthidate • Methylphenidate • Phencyclidine • Pipradrol; Pyrrolidines: Diphenylprolinol • Methylenedioxypyrovalerone (MDPV) • Naphyrone • Prolintane • Pyrovalerone; Tropanes: β-CPPIT • Altropane • Brasofensine • CFT • Cocaine • Dichloropane • Difluoropine • FE-β-CPPIT • FP-β-CPPIT • Ioflupane (¹²³I) • Iometopane • RTI-112 • RTI-113 • RTI-121 • RTI-126 • RTI-150 • RTI-177 • RTI-229 • RTI-336 • Tenocyclidine • Tesofensine • Troparil • Tropoxane • WF-11 • WF-23 • WF-31 • WF-33; Others: Adrafinil • Armodafinil • Amfonelic acid • Amineptine • Benzatropine (Benztropine) • Bromantane • BTQ • BTS-74,398 • Bupropion (Amfebutamone) • Ciclazindol • Diclofensine • Dimethocaine • Diphenylpyraline • Dizocilpine • DOV-102,677 • DOV-21,947 • DOV-216,303 • Etybenzatropine (Ethylbenztropine) • EXP-561 • Fencamine • Fencamfamine • Fezolamine • GYKI-52,895 • Indatraline • Ketamine • Lefetamine • Levophacetoperane • LR-5182 • Manifaxine • Mazindol • Medifoxamine • Mesocarb • Modafinil • Nefopam • Nomifensine • NS-2359 • O-2172 • Pridefrine • Propylamphetamine • Radafaxine • SEP-225,289 • SEP-227,162 • Sertraline • Sibutramine • Tametraline • Tedatioxetine • Tripelennamine

Vesicular

VMAT inhibitors	Deserpidine • Ibogaine • Reserpine • Tetrabenazine

Releasing agents

Morpholines: Fenbutrazate • Morazone • Phendimetrazine • Phenmetrazine; Oxazolines: 4-Methylaminorex (4-MAR, 4-MAX) • Aminorex • Clominorex • Cyclazodone • Fenozolone • Fluminorex • Pemoline • Thozalinone; Phenethylamines (also amphetamines, cathinones, phentermines, etc): 2-Hydroxyphenethylamine (2-OH-PEA) • 4-CAB • 4-Methylamphetamine (4-MA) • 4-Methylmethamphetamine (4-MMA) • Alfetamine • Amfecloral • Amfepentorex • Amfepramone • Amphetamine (Dextroamphetamine, Levoamphetamine) • Amphetaminil • β-Methylphenethylamine (β-Me-PEA) • Benzodioxolylbutanamine (BDB) • Benzodioxolylhydroxybutanamine (BOH) • Benzphetamine • Buphedrone • Butylone • Cathine • Cathinone • Clobenzorex • Clortermine • D-Deprenyl • Dimethoxyamphetamine (DMA) • Dimethoxymethamphetamine (DMMA) • Dimethylamphetamine • Dimethylcathinone (Dimethylpropion, metamfepramone) • Ethcathinone (Ethylpropion) • Ethylamphetamine • Ethylbenzodioxolylbutanamine (EBDB) • Ethylone • Famprofazone • Fenethylline • Fenproporex • Flephedrone • Fludorex • Furfenorex • Hordenine • Lophophine (Homomyristicylamine) • Mefenorex • Mephedrone • Methamphetamine (Desoxyephedrine, Methedrine; Dextromethamphetamine, Levomethamphetamine) • Methcathinone (Methylpropion) • Methedrone • Methoxymethylenedioxyamphetamine (MMDA) • Methoxymethylenedioxymethamphetamine (MMDMA) • Methylbenzodioxolylbutanamine (MBDB) • Methylenedioxyamphetamine (MDA, tenamfetamine) • Methylenedioxyethylamphetamine (MDEA) • Methylenedioxyhydroxyamphetamine (MDOH) • Methylenedioxymethamphetamine (MDMA) • Methylenedioxymethylphenethylamine (MDMPEA, homarylamine) • Methylenedioxyphenethylamine (MDPEA, homopiperonylamine) • Methylone • Ortetamine • Parabromoamphetamine (PBA) • Parachloroamphetamine (PCA) • Parafluoroamphetamine (PFA) • Parafluoromethamphetamine (PFMA) • Parahydroxyamphetamine (PHA) • Paraiodoamphetamine (PIA) • Paredrine (Norpholedrine, Oxamphetamine) • Phenethylamine (PEA) • Pholedrine • Phenpromethamine • Prenylamine • Propylamphetamine • Tiflorex (Flutiorex) • Tyramine (TRA) • Xylopropamine • Zylofuramine; Piperazines: 2,5-Dimethoxy-4-bromobenzylpiperazine (2C-B-BZP) • Benzylpiperazine (BZP) • Methoxyphenylpiperazine (MeOPP, paraperazine) • Methylbenzylpiperazine (MBZP) • Methylenedioxybenzylpiperazine (MDBZP, piperonylpiperazine); Others: 2-Amino-1,2-dihydronaphthalene (2-ADN) • 2-Aminoindane (2-AI) • 2-Aminotetralin (2-AT) • 4-Benzylpiperidine (4-BP) • 5-IAI • Clofenciclan • Cyclopentamine • Cypenamine • Cyprodenate • Feprosidnine • Gilutensin • Heptaminol • Hexacyclonate • Indanylaminopropane (IAP) • Indanorex • Isometheptene • Methylhexanamine • Naphthylaminopropane (NAP) • Octodrine • Phthalimidopropiophenone • Propylhexedrine (Levopropylhexedrine) • Tuaminoheptane (Tuamine)

Enzyme inhibitors

Anabolism

PAH inhibitors	3,4-Dihydroxystyrene

TH inhibitors	3-Iodotyrosine • Aquayamycin • Bulbocapnine • Metirosine • Oudenone

AAAD/DDC inhibitors	Benserazide • Carbidopa • Genistein • Methyldopa

Catabolism

MAO inhibitors	Nonselective: Benmoxin • Caroxazone • Echinopsidine • Furazolidone • Hydralazine • Indantadol • Iproclozide • Iproniazid • Isocarboxazid • Isoniazid • Linezolid • Mebanazine • Metfendrazine • Nialamide • Octamoxin • Paraxazone • Phenelzine • Pheniprazine • Phenoxypropazine • Pivalylbenzhydrazine • Procarbazine • Safrazine • Tranylcypromine; MAO-A selective: Amiflamine • Bazinaprine • Befloxatone • Befol • Brofaromine • Cimoxatone • Clorgiline • Esuprone • Harmala alkaloids • Methylene Blue • Metralindole • Minaprine • Moclobemide • Pirlindole • Sercloremine • Tetrindole • Toloxatone • Tyrima; MAO-B selective: D-Deprenyl • L-Deprenyl (Selegiline) • Ladostigil • Lazabemide • Milacemide • Pargyline • Rasagiline • Safinamide

COMT inhibitors	Entacapone • Tolcapone

DBH inhibitors	Disulfiram • Dopastin • Fusaric acid • Nepicastat • Tropolone

Others

Precursors	L-Phenylalanine → L-Tyrosine → L-DOPA (Levodopa)

Cofactors	Ferrous iron (Fe²⁺) • Tetrahydrobiopterin • Vitamin B₃ (Niacin, Nicotinamide → NADPH) • Vitamin B₆ (Pyridoxine, Pyridoxamine, Pyridoxal → Pyridoxal phosphate) • Vitamin B₉ (Folic acid → Tetrahydrofolic acid) • Vitamin C (Ascorbic acid) • Zinc (Zn²⁺)

Others	Activity enhancers: Benzofuranylpropylaminopentane (BPAP) • Phenylpropylaminopentane (PPAP); Toxins: Oxidopamine (6-Hydroxydopamine)

List of dopaminergic drugs

Tolcapone

Contents

Uses

Chemistry

Pharmacology

See also

References