TASMAR (tolcapone)
TASMAR is indicated as an adjunctive treatment to levodopa and carbidopa for the management of signs and symptoms of idiopathic Parkinson's disease. Due to the risk of potentially fatal acute fulminant liver failure, the drug is reserved for patients experiencing symptom fluctuations who have not responded to or are not candidates for other adjunctive therapies. Clinical benefit must be observable within three weeks of initiation, or the medication should be discontinued.
How TASMAR Works
Tolcapone functions as a selective and reversible inhibitor of catechol-O-methyltransferase (COMT), the primary enzyme responsible for metabolizing levodopa when a decarboxylase inhibitor is present. By blocking this enzyme, tolcapone sustains plasma levels of levodopa, leading to more constant dopaminergic stimulation in the brain. This mechanism enhances the effects of levodopa on the signs and symptoms of Parkinson's disease.
Development Insights
Details
- Status
- Prescription
- First Approved
- 1998-01-29
- Routes
- ORAL
- Dosage Forms
- TABLET
TASMAR Approval History
What TASMAR Treats
1 indicationsTASMAR is approved for 1 conditions since its original approval in 1998. These indications span multiple therapeutic areas including oncology, immunology, and more.
- Parkinson's Disease
TASMAR Boxed Warning
WARNING Because of the risk of potentially fatal, acute fulminant liver failure, TASMAR (tolcapone) should ordinarily be used in patients with Parkinson's disease on l-dopa/carbidopa who are experiencing symptom fluctuations and are not responding satisfactorily to or are not appropriate candidates for other adjunctive therapies (see INDICATIONS and DOSAGE AND ADMINISTRATION sections). Because of the risk of liver injury and because TASMAR, when it is effective, provides an observable symptomati...
WARNING Because of the risk of potentially fatal, acute fulminant liver failure, TASMAR (tolcapone) should ordinarily be used in patients with Parkinson's disease on l-dopa/carbidopa who are experiencing symptom fluctuations and are not responding satisfactorily to or are not appropriate candidates for other adjunctive therapies (see INDICATIONS and DOSAGE AND ADMINISTRATION sections). Because of the risk of liver injury and because TASMAR, when it is effective, provides an observable symptomatic benefit, the patient who fails to show substantial clinical benefit within 3 weeks of initiation of treatment, should be withdrawn from TASMAR. TASMAR therapy should not be initiated if the patient exhibits clinical evidence of liver disease or two SGPT/ALT or SGOT/AST values greater than the upper limit of normal. Patients with severe dyskinesia or dystonia should be treated with caution (see PRECAUTIONS: Rhabdomyolysis ). PATIENTS WHO DEVELOP EVIDENCE OF HEPATOCELLULAR INJURY WHILE ON TASMAR AND ARE WITHDRAWN FROM THE DRUG FOR ANY REASON MAY BE AT INCREASED RISK FOR LIVER INJURY IF TASMAR IS REINTRODUCED. ACCORDINGLY, SUCH PATIENTS SHOULD NOT ORDINARILY BE CONSIDERED FOR RETREATMENT. Cases of severe hepatocellular injury, including fulminant liver failure resulting in death, have been reported in postmarketing use. As of May 2005, three cases of fatal fulminant hepatic failure have been reported from more than 40,000 patient years of worldwide use. This incidence may be 10- to 100-fold higher than the background incidence in the general population. Underreporting of cases may lead to significant underestimation of the increased risk associated with the use of TASMAR. All three cases were reported within the first six months of initiation of treatment with TASMAR. Analysis of the laboratory monitoring data in over 3,400 TASMAR-treated patients participating in clinical trials indicated that increases in SGPT/ALT or SGOT/AST, when present, generally occurred within the firs
TASMAR Competitive Set
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Direct competitors
Same target(s) AND same indication — head-to-head.
Indication competitors
Same indication, different mechanism — what else might this patient receive?
Filters applied: drops same-active-ingredient (505(b)(2) reformulations), route-mismatch (topical vs systemic), and cross-therapeutic-area matches in same-indication rings.
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Clinical Trial Registry
13 trials| Trial | Sponsor ID | Phase | Status | Title |
|---|---|---|---|---|
| NCT03904498 | 19-2335 R01AA026859 | Ph 2 | completed | COMT Inhibition Among Individuals With Comorbid AUD/ADHD |
| NCT05624528 | IRB22-1729 | Ph 2 | active not recruiting | A Clinical Trial of Tolcapone in Obsessive Compulsive Disorder |
| NCT00604591 results posted | AAAF4151 5R00NS060766 | Ph 2 | completed | Effects of Tolcapone on Frontotemporal Dementia |
| NCT02630043 | NMTRC011 | Ph 1 | terminated | Trial of Tolcapone With Oxaliplatin for Neuroblastoma |
| NCT02949934 results posted | Pro00050157 P50AA010761 | Ph 2 | completed | Effects of Cortical Dopamine Regulation on Drinking, Craving, and Cognitive Control |
| NCT00927563 results posted | 0901M58441 | Ph 2 | completed | Tolcapone Treatment of Pathological Gambling |
| NCT02929485 | 2011-11-3748 | Ph 4 | withdrawn | Dopaminergic Modulation of Frontostriatal Function With a Dopamine Agonist and COMT Inhibitor |
| NCT02740582 results posted | Tolcapone Lab Bar | Ph 2 | completed | Effects of Tolcapone on Decision Making and Alcohol Intake in Alcohol Users |
| NCT03633591 | TOLC101MR 2017-003070-13 | Ph 1 | completed | A Study Assessing the Safety and Pharmacokinetic Profile of Modified Release Formulations of Tolcapone |
| NCT01202955 results posted | 808250 | Ph 2 | completed | Pilot Study of Tolcapone in Smokers |
| NCT02080715 | COMT and vigilance | Ph 1 | completed | Role of the Catechol-O-methyltransferase (COMT) in the Physiological Regulation of Vigilance |
| NCT01001520 results posted | 809858 R01DA026849 | Ph 2 | completed | Neural Substrates in Nicotine Withdrawal |
| NCT00906828 DuoCOMT | DuoCOMT | Ph 4 | completed | Pharmacokinetics of Levodopa/Carbidopa Infusion With and Without Oral Catechol-O-methyl Transferase (COMT) Inhibitors |
Active Pipeline
Ongoing clinical trials by development phase
Key Completed Trials
Completed studies with published results, ranked by significance
Trial Timeline
Full development history with FDA approval milestones
Understanding FDA Approval Types
| Count | Type | What it means |
|---|---|---|
| - | ORIG | Original approval - drug first enters market |
| - | SUPPL - Efficacy | New indication (new disease/condition approved) |
| - | SUPPL - Labeling | Label text changes (warnings, dosing updates) |
| - | SUPPL - Manufacturing | Production changes (new facility) |
| - | SUPPL - Chemistry | Formulation changes (new dosage strength) |
Green lines in the timeline show ORIG and Efficacy approvals - the clinically meaningful milestones.
TASMAR FDA Label Details
Indications & Usage
FDA Label (PDF)TASMAR is indicated for the treatment of Parkinson's Disease.
WARNING Because of the risk of potentially fatal, acute fulminant liver failure, TASMAR (tolcapone) should ordinarily be used in patients with Parkinson's disease on l-dopa/carbidopa who are experiencing symptom fluctuations and are not responding satisfactorily to or are not appropriate candidates ...
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Data Sources
Data sourced from official FDA and NIH databases. Click links to verify on original sources.
How We Calculate These Metrics
Trial Activity Stage
Measures the current development activity pattern based on trial phases, status, and trends. Important: This measures R&D activity, not commercial lifecycle.
Trial statuses: "Active" means recruiting or ongoing. "Completed" means reached planned endpoint. "Terminated" means stopped early—often due to safety, efficacy, or business reasons.
- Growth: High proportion of early-phase trials (Phase 1/2), active development
- Expansion: Significant Phase 3 activity, approaching or pursuing approvals
- Mature: Substantial Phase 4 post-marketing studies
- Stable: Mixed phase distribution, steady development
- Declining: Low active trial ratio, reduced R&D investment