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Drug

Tolcapone

Approved · EMA
Emerging researchLate-stage development
Also known as Tasmar, Tolcapon, Tolcapona, (3,4-dihydroxy-5-nitrophenyl)(4-methylphenyl)methanone+4 more

Tasmar, Tolcapon, Tolcapona, (3,4-dihydroxy-5-nitrophenyl)(4-methylphenyl)methanone, 3,4-dihydroxy-4'-methyl-5-nitrobenzophenone, 3,4-dihydroxy-5-nitro-4'-methylbenzophenone, 4'-methyl-3,4-dihydroxy-5-nitrobenzophenone, Tolcaponum.

RxNorm72937ChEMBLCHEMBL1324UNIICIF6334OLY
2
Research papers
1
Active clinical trials
1
Regulatory events
Latest activity
beta

Recent clinical, regulatory, research and industry developments relating to this drug.

A Double-Blind, Randomized, Placebo-Controlled Study of Tolcapone for OCD

Clinical trial2026-06-01Primary completion · ClinicalTrials.gov

COMT Inhibition as a Potential Therapeutic Target Among Individuals With Comorbid Alcohol Use Disorder and Attention-Deficit/Hyperactivity Disorder

Clinical trial2026-03-09Completed · ClinicalTrials.gov

Incorporating Drug Metabolism by the Human Gut Microbiome Into Personalized Medicine

Clinical trial2025-09-23Completed · ClinicalTrials.gov

Remediation of Impaired Self-Regulation in Patients With Mild TBI

Clinical trial2025-09-22Results posted · ClinicalTrials.gov

Evaluation of the Efficacy of Tolcapone as a Genotype-based Targeted Cognitive Enhancer in Schizophrenia, Based on the Polymorphism rs4680

Clinical trial2025-08-01Primary completion · ClinicalTrials.gov

Investigation of the Dopamine System in Frontotemporal Dementia

Clinical trial2024-08-28Results posted · ClinicalTrials.gov

Dopaminergic Mechanisms Underlying Human Social Behavior: A Multimodal Approach

Clinical trial2023-12-31Completed · ClinicalTrials.gov

Effects of Cortical Dopamine Regulation on Drinking, Craving, and Cognitive Control

Clinical trial2023-06-09Results posted · ClinicalTrials.gov

Tolcapone Treatment of Pathological Gambling: An Open-Label Study

Clinical trial2023-02-23Results posted · ClinicalTrials.gov

The catechol-O-methyltransferase inhibitor tolcapone modulates alcohol consumption and impulsive choice in alcohol use disorder.

Research2020-07-02Psychopharmacology

Right inferior frontal cortex activity correlates with tolcapone responsivity in problem and pathological gamblers.

Research2016-12-20NeuroImage. Clinical

Approval: Tasmar (EMA)

Regulatory1997-08-27EMA

Profile

Identifiers & mechanism

Canonical identifiers, marketed brand names and mechanism, resolved across RxNorm, ChEMBL and ATC.

Canonical name
Tolcapone
Aliases & brands
TasmarTolcaponTolcapona(3,4-dihydroxy-5-nitrophenyl)(4-methylphenyl)methanone3,4-dihydroxy-4'-methyl-5-nitrobenzophenone3,4-dihydroxy-5-nitro-4'-methylbenzophenone4'-methyl-3,4-dihydroxy-5-nitrobenzophenoneTolcaponum
RxNorm CUI
72937
ChEMBL ID
CHEMBL1324
UNII
CIF6334OLY
Regulatory jurisdictions
ema

Regulatory timeline

1 event

The complete regulatory record, grouped by authority — approvals, safety advisories and label changes. Each authority shows its most recent events; expand one to read its full history.

Earliest approval
1997-08-27
Latest approval
1997-08-27
Authorities
EMA
Total events
1
emaEuropean Medicines Agency· 1 event
1997-08-27Approval
Approval: Tasmar (EMA)
Indication: Tasmar is indicated in combination with levodopa / benserazide or levodopa / carbidopa for use in patients with levodopa-responsive idiopathic Parkinson’s disease and motor… Show full indication

Tasmar is indicated in combination with levodopa / benserazide or levodopa / carbidopa for use in patients with levodopa-responsive idiopathic Parkinson’s disease and motor fluctuations, who failed to respond to or are intolerant of other catechol-O-methyltransferase (COMT) inhibitors. Because of the risk of potentially fatal, acute liver injury, Tasmar should not be considered as a first-line adjunct therapy to levodopa / benserazide or levodopa / carbidopa. Since Tasmar should be used only in combination with levodopa / benserazide and levodopa / carbidopa, the prescribing information for these levodopa preparations is also applicable to their concomitant use with Tasmar.

Evidence ↗

Contains information from the European Medicines Agency (European Medicines Agency), © EMA, reused under CC BY 4.0.

Clinical trials

26 trials

The current development programme across all trial phases — status mix, phase distribution and the late-stage studies shaping the evidence base.

Development programme
CLINICALTRIALS.GOV · LIVE REGISTRY
26
registered trials across all phases
LATEST COMPLETION 2026
1
Active studies
6
Late-stage (III+)
18
Completed
7
Discontinued
PHASE DISTRIBUTIONn = 26
Early Phase 13Phase 15Phase 212Phase 2 / 31Phase 42Phase N / A3

Late-stage studies

Phase III+ trials still open or recently active — where late-stage evidence is being generated.

Dopaminergic Modulation of Frontostriatal Function With a Dopamine Agonist and COMT Inhibitor

WithdrawnPH IVUniversity of California, Berkeley2018

Pharmacokinetics of Levodopa in Patients With Parkinson's Disease Treated With Levodopa/Carbidopa Infusion With and Without Oral COMT Inhibitors

CompletedPH IVUppsala Universityn=102009

Tolcapone Treatment of Obsessive Compulsive Disorder: A Double-Blind, Placebo-Controlled, Cross-Over Pilot Study

CompletedPH II/IIIUniversity of Chicagon=202020

Recent completions

Trials that read out recently, adding to the completed evidence base.

COMT Inhibition as a Potential Therapeutic Target Among Individuals With Comorbid Alcohol Use Disorder and Attention-Deficit/Hyperactivity Disorder

CompletedPH IIUniversity of Colorado, Denvern=232026

Incorporating Drug Metabolism by the Human Gut Microbiome Into Personalized Medicine

CompletedPH IRutgers, The State University of New Jerseyn=172025

Dopaminergic Mechanisms Underlying Human Social Behavior: A Multimodal Approach

CompletedPH IUniversity of California, Berkeleyn=702023

Remediation of Impaired Self-Regulation in Patients With Mild TBI

CompletedPH IVA Office of Research and Developmentn=552021

Effects of Cortical Dopamine Regulation on Drinking, Craving, and Cognitive Control

CompletedPH IIMedical University of South Carolinan=902021

Tolcapone Treatment of Obsessive Compulsive Disorder: A Double-Blind, Placebo-Controlled, Cross-Over Pilot Study

CompletedPH II/IIIUniversity of Chicagon=202020

Research activity

2 papers

Key research shaping understanding of this drug, combining the latest publications with the most influential evidence.

Publications over time
20172020
Major research themes2
Prefrontal Cortex1Ventral Striatum1
Journals, researchers & institutions
Top journals
  • NeuroImage. Clinical1
  • Psychopharmacology1
Leading researchers
  • Kayser AS2
  • Mitchell JM2
  • Coker AR1
  • Miller CS1
  • Peters J1
  • Vega T1
  • Vega TA1
  • Weinstein D1
Leading institutions
free-text, unnormalised
  • University of California2
  • University of Cologne1
References & data sources
  • RxNorm (U.S. National Library of Medicine) — drug identity
  • ChEMBL (EMBL-EBI) & UniProt — pharmacology and targets
  • Europe PMC — research literature
  • ClinicalTrials.gov — clinical trials
  • Regulatory event sources are credited in the Regulatory Timeline above.