COMT inhibitor
Catechol-O-methyltransferase inhibitor
- Levodopa and catecholamines last longer
- Extends each levodopa dose — fewer “off” periods in Parkinson disease
- Only works alongside levodopa
- Dopaminergic excess → dyskinesia
Drugs with this mechanism (3)
- Entacapone — Peripheral COMT inhibitor extending levodopa; turns urine orange.
- Opicapone — Long-acting COMT inhibitor for Parkinson wearing-off; low pill burden and no hepatotoxicity signal.
- Tolcapone — The COMT inhibitor that crosses into brain - and carries a boxed hepatotoxicity warning.
Self-check
- How does COMT inhibition change levodopa’s off periods?
Reduces them by extending each dose. - What dopaminergic toxicity can COMT inhibition cause?
Dyskinesia.
All mechanisms · Open COMT inhibitor in the interactive console ↗