Entacapone
Comtan (entacapone) is a catechol-O-methyltransferase (COMT) inhibitor used as an adjunct therapy alongside levodopa/carbidopa to treat Parkinson's disease. It works by preventing the breakdown of levodopa in the periphery, prolonging its therapeutic effect and reducing off periods. This medication is specifically indicated for patients experiencing motor fluctuations on levodopa therapy.
Comtan is a Parkinson's disease adjunct medication that enhances levodopa effectiveness by inhibiting its breakdown.
Key facts at a glance
- RxNorm
- 262112
- Generic
- Comtan
- Class
- brand-name
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- —
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Comtan is indicated as an adjunct to levodopa/carbidopa therapy for the treatment of end-of-dose motor fluctuations in patients with Parkinson's disease. It is not used as monotherapy.
Comtan reversibly inhibits the enzyme catechol-O-methyltransferase (COMT), which normally breaks down levodopa in the periphery. By preventing this breakdown, more levodopa reaches the brain, extending its duration of action and reducing 'off' episodes.
Common side effects include dyskinesia, diarrhea, nausea, and urine/sweat discoloration (harmless brown-orange). Patients should inform their doctor of liver problems. Comtan must always be used with levodopa/carbidopa and may require levodopa dose adjustment.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy