Tolcapone (Tasmar) Drug for Parkinson's Disease: Use, Side Effects, Interactions

Tolcapone
(Tasmar, United States and Canada)

Please note that Tolcapone (Tasmar) has been withdrawn from the Canadian and European markets due to reports of serious liver toxicities.

Use:

Tolcapone or Tasmar is used in Parkinson's therapy along with levodopa.

How It Works:

Tolcapone or Tasmar inhibits an enzyme known as COMT (catechol-O-methyl transferase). This enzyme breaks down levodopa, and by inhibiting it, more levodopa remains in the body - specifically in the nervous system. Levodopa is the mainstay of Parkinson's therapy, and Tolcapone or Tasmar means that levodopa is more effective.

Side Effects:

Tolcapone or Tasmar's most common side effects include diarrhea, sleep disturbances, and hallucinations. Dyskinesia or movement difficulties can occur and unfortunately may be difficult to distinguish from the Parkinson's condition.

Cautions for People:

Tolcapone or Tasmar can affect liver enzymes and people with liver conditions or at risk for liver disease must be followed closely.
Adverse effects occur more often in women than in men, but it is unclear why. Women need to be monitored closely.

Drug Interactions:

Because Tolcapone or Tasmar can affect liver enzymes, other drugs that are metabolised by liver enzymes, for example warfarin, may require monitoring and dosage adjustments.
Because it affects the COMT enzyme, potential interactions may occur with other drugs that are also affected by this enzyme, for example monoamine oxidase inhibitor (MAOI) antidepressant drugs.
Tolcapone or Tasmar is intended to be used along with levodopa.

Further Reading:

Neurology 1997;49:1

Added to Virtual Drugstore December 1997.

The relevant product monographs must be regarded as the appropriate sources of prescribing information.