Results for the substance tolcapone

Tolcapone is a medication used in the treatment of Parkinson’s disease, particularly in patients who do not respond adequately to other therapies. It is a catechol-O-methyltransferase (COMT) inhibitor, an enzyme that breaks down dopamine. By inhibiting COMT, tolcapone increases the levels of dopamine available in the brain, thereby improving the control of motor symptoms such as rigidity, tremor, and bradykinesia.

The mechanism of action of tolcapone involves blocking COMT activity both peripherally and centrally. This reduces the breakdown of levodopa (the precursor of dopamine) and extends the duration of levodopa’s activity in the body. As a result, tolcapone is used in combination with levodopa/carbidopa to prolong its effects and reduce motor fluctuations ('on-off' phenomena).

Tolcapone is administered orally, usually three times a day, alongside levodopa/carbidopa. It is important for patients to follow the prescribed dosage and undergo regular monitoring, as tolcapone can cause significant side effects.

While effective, tolcapone may cause side effects, the most common being nausea, diarrhea, drowsiness, dizziness, and confusion. In rare cases, severe liver toxicity may occur, which is why liver function must be monitored periodically. Tolcapone is contraindicated in patients with pre-existing liver conditions or hypersensitivity to the active substance. Its use is reserved for cases where other treatments are insufficient to control symptoms.