Tolcapone

273.24

273.24

CIF6334OLY

DTXSID3023685

C47762

N04BX01|N - Nervous system

2914710000

103

3.3

yellow

1.419±0.06 g/cm3(Predicted)

141-143 °C

485.6±45.0 °C(Predicted)

205.7±17.2 °C

1.661

DMSO: ≥15mg/mL

-20°C Freezer

Ⅲ

UN 3077 9 / PGIII

50

61

PC4952500

N

P273

H400

|Warning|H400 (100%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]|P273, P391, and P501|Aggregated GHS information provided by 39 companies from 1 notifications to the ECHA C&L Inventory.

LD50 = 1600 mg/kg (Orally in rats)

Tolcapone has been reported to cause serum aminotransferase elevations above 3 times the upper limit of normal in 1% to 5% of patients. While these abnormalities are usually asymptomatic and self-limiting, some persist if therapy is continued and resolved only with stopping tolcapone. More importantly, tolcapone has been implicated in several cases of severe, clinically apparent acute liver injury and at least three cases of death from acute liver failure. The onset of injury was insidious, arising 1 to 5 months after starting treatment. The pattern of serum enzyme elevations was hepatocellular and the clinical phenotype was similar to acute viral hepatitis. Immunoallergic manifestations were not present, but some patients had autoantibodies of unclear significance. Because of these reports, regular monitoring of serum aminotransferase levels has been mandated (every 2 to 4 weeks for the first 6 months of treatment and as clinically indicated thereafter) during tolcapone therapy, and treatment should be promptly discontinued if ALT or AST levels rise above twice the upper limit of the normal range or if signs or symptoms of liver injury are present.

> 99.9% (to serum albumin)

Used as an adjunct to levodopa/carbidopa therapy for the symptomatic treatment of Parkinson's Disease. This drug is generally reserved for patients with parkinsonian syndrome receiving levodopa/carbidopa who are experiencing symptom fluctuations and are not responding adequately to or are not candidates for other adjunctive therapies.|FDA Label|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.

Tolcapone is a catechol-O-methyltransferase inhibitor used in the therapy of Parkinson disease as adjunctive therapy in combination with levodopa and carbidopa. Tolcapone has been associated with serum enzyme elevations during treatment and with several instances of clinically apparent acute liver injury, which can be severe and even fatal.

Parkinson Disease Agents

Tolcapone is a potent, selective, and reversible inhibitor of catechol-O-methyltransferase (COMT). In humans, COMT is distributed throughout various organs. COMT catalyzes the transfer of the methyl group of S-adenosyl-L-methionine to the phenolic group of substrates that contain a catechol structure. Physiological substrates of COMT include dopa, catecholamines (dopamine, norepinephrine, epinephrine) and their hydroxylated metabolites. The function of COMT is the elimination of biologically active catechols and some other hydroxylated metabolites. COMT is responsible for the elimination of biologically active catechols and some other hydroxylated metabolites. In the presence of a decarboxylase inhibitor, COMT becomes the major metabolizing enzyme for levodopa catalyzing it to 3-methoxy-4-hydroxy-L-phenylalanine (3-OMD) in the brain and periphery. When tolcapone is given in conjunction with levodopa and an aromatic amino acid decarboxylase inhibitor, such as carbidopa, plasma levels of levodopa are more sustained than after administration of levodopa and an aromatic amino acid decarboxylase inhibitor alone. It is believed that these sustained plasma levels of levodopa result in more constant dopaminergic stimulation in the brain, leading to greater effects on the signs and symptoms of Parkinson's disease in patients as well as increased levodopa adverse effects, sometimes requiring a decrease in the dose of levodopa.

Agents used in the treatment of Parkinson's disease. The most commonly used drugs act on the dopaminergic system in the striatum and basal ganglia or are centrally acting muscarinic antagonists. (See all compounds classified as Antiparkinson Agents.)|Compounds and drugs that inhibit or block the activity of CATECHOL O-METHYLTRANSFERASE enzymes. Drugs in this class are used in management of central nervous system disorders such as PARKINSON DISEASE. (See all compounds classified as Catechol O-Methyltransferase Inhibitors.)

Rapidly absorbed (absolute bioavailability is about 65%)|Tolcapone is almost completely metabolized prior to excretion, with only a very small amount (0.5% of dose) found unchanged in urine. The glucuronide conjugate of tolcapone is mainly excreted in the urine but is also excreted in the bile.|9 L|7 L/h

The main metabolic pathway of tolcapone is glucuronidation|Tolcapone has known human metabolites that include (2S,3S,4S,5R)-3,4,5-trihydroxy-6-[2-hydroxy-4-(4-methylbenzoyl)-6-nitrophenoxy]oxane-2-carboxylic acid.

2-3.5 hours

The precise mechanism of action of tolcapone is unknown, but it is believed to be related to its ability to inhibit COMT and alter the plasma pharmacokinetics of levodopa, resulting in an increase in plasma levodopa concentrations. The inhibition of COMT also causes a reduction in circulating 3-OMD as a result of decreased peripheral metabolism of levodopa. This may lead to an increase distribution of levodopa into the CNS through the reduction of its competitive substrate, 3-OMD, for transport mechanisms. Sustained levodopa concentrations presumably result in more consistent dopaminergic stimulation, resulting in greater reduction in the manifestations of parkinsonian syndrome.

3,4 Dihydroxy 5' methyl 5 nitrobenzophenone

Human drugs -> Tasmar -> EMA Drug Category|Anti-Parkinson drugs, Other dopaminergic agents -> Human pharmacotherapeutic group|Human Drugs -> FDA Approved Drug Products with Therapeutic Equivalence Evaluations (Orange Book) -> Active Ingredients