For Non-US Residents

How It Works


The biology of Parkinson’s disease and its treatment involves the complicated interaction of brain chemicals and enzymes. When patients first start on levodopa or levodopa/carbidopa combination therapy, their improvement is often dramatic. However, after a few years, this therapy becomes less and less effective, which leads to an increase in symptoms (this is called "wearing off").


TASMAR® (tolcapone) inhibits catechol-O-methyltransferase (COMT), an enzyme that catalyzes the metabolization of levodopa into 3-O-methyldopa. This provides a prolonged maintenance of serum levodopa levels, which may provide a longer clinical response to levodopa treatments.


Therefore, TASMAR is most effectively prescribed to prolong the effectiveness of levodopa and carbidopa treatments after their clinical effectiveness has been reduced due to the progression of the disease. It can also be prescribed if a patient is not responding well to, or is not an appropriate candidate for, other adjunctive therapies.

TASMAR SHOULD NOT BE USED BY PATIENTS UNTIL THERE HAS BEEN A COMPLETE DISCUSSION OF THE RISKS AND THE PATIENT HAS PROVIDED WRITTEN INFORMED CONSENT (SEE PATIENT ACKNOWLEDGEMENT FORM).

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).

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).

Laboratory Tests: Although a program of frequent laboratory monitoring for evidence of hepatocellular injury is deemed essential, it is not clear that periodic monitoring of liver enzymes will prevent the occurrence of fulminant liver failure. However, it is generally believed that early detection of drug-induced hepatic injury along with immediate withdrawal of the suspect drug enhances the likelihood for recovery. Accordingly, the following liver monitoring program is recommended.

Please see accompanying complete prescribing information including BOXED warning.