What Is Tolcapone?

Tolcapone is a drug that may be prescribed to individuals with Parkinson's disease. It is generally used as an adjunct to levodopa/carbidopa. These drugs do not cure Parkinson's disease, but together, they may inhibit the signs and symptoms of Parkinson's. Tolcapone is marketed under the brand name Tasmar®. It can cause side effects, some of which are more serious than others. Individuals who are using the drug must remain under a doctor's care to have blood work performed on a regular basis.

Tolcapone belongs to a group of drugs that are often referred to as anti-Parkinson's agents. Most often, it is prescribed as an adjunct to levodopa/carbidopa. Together, the drugs work to reduce the signs and symptoms of Parkinson's disease by increasing an individual's dopamine levels. In many cases, an individual suffering from Parkinson's is prescribed a levodopa/carbidopa combination first, and over time, the effects of the prescription weaken. Tolcapone is then prescribed in conjunction with levodopa/carbidopa to increase and lengthen the effects of levodopa/carbidopa.

The signs and symptoms of Parkinson's disease are caused by dopamine deficiency in the brain. In many people suffering from Parkinson's, Tolcapone increases dopamine levels and reduces the symptoms of Parkinson's. The drug works by inhibiting the activity of the naturally occurring enzyme catechol-O-methyltransferase (COMT). This enzyme inactivates dopamine in the body, causing a dopamine deficiency which gives rise to the symptoms of Parkinson's. Tolcapone and other anti-Parkinson's agents work against the dopamine inhibitor catechol-O-methyltransferase.

Tolcapone is traditionally prescribed in tablet form, and can cause various side effects. The most common side effects include nausea, dizziness, vomiting, and diarrhea. Some individuals using the drug also experience excessive dreaming and have difficulty sleeping. It is important for any individual taking the drug to discuss side effects with a doctor. Some serious side effects may indicate an adverse reaction to the drug. These include fainting or lightheadedness, confusion, hallucinations, dark urine, and right-upper-belly pains.

Before a person begins taking Tolcapone, it is important to discuss any other medications, whether they are prescription or non-prescription, with the prescribing doctor and pharmacist. Anticoagulants, drugs that cause drowsiness, and other dopamine inhibitors may interact with Tolcapone in an adverse way. Patients taking Tolcapone who plan to have surgery, including dental surgery, should inform the surgeon or dentist that they are using the drug. Women who are pregnant or breast feeding should discuss their situation with a doctor before taking the drug.