COMT Toxicity—

Adverse effects related partly to increased levels of levodopa include dyskinesias, gastrointestinal distress, and postural hypotension. Levodopa dose reductions may be needed for the first few days of COMT inhibitor use. Other side effects include sleep disturbances and orange discoloration of the urine.Tolcapone increases liver enzymes and has caused acute hepatic failure, necessitating routine monitoring of liver function tests and signed patient consent for use in the United States.