(FDA approved in bold)

• Parkinsonism, including Parkinson’s disease (PD)

• Highly selective peripherally acting inhibitor of catechol-O-methyltransferase (COMT), an important enzyme in dopamine metabolism. Use with levodopa/carbidopa enables more levodopa to enter the brain and prevents the end-of-dose wearing-off seen in PD. Entacapone has less activity on COMT in the brain, meaning the drug is not considered centrally active

• PD – hours-weeks

• PD – a majority (58%) of patients taking 800 mg or more per day of levodopa will lower levodopa dose, on average by 25% of the total after starting entacapone

• If end-of-dose wearing-off does not improve with entacapone and levodopa, decrease the dosing interval, add a dopamine agonist, monoamine oxidase B (MAO-B) inhibitor or consider neurosurgical options. For sudden, unpredictable wearing–off, consider apomorphine

• Entacapone is used only as an adjunctive medication in PD with levodopa
  
• For dyskinesias, lower dose of levodopa or add a dopamine agonist
  
• Younger patients with bothersome tremor: anticholinergics may help
  
• For severe motor fluctuations and/or dyskinesias with good “on” time, functional neurosurgery is an option
  
• Amantadine may help suppress dyskinesias, although benefit is often short-lived
  
• Depression is common in PD and may respond to low dose SSRIs
  
• Cognitive impairment/dementia is common in mid-late stage PD and may improve with acetylcholinesterase inhibitors

• None required