How do you switch/cross-titrate regular Levodopa to Rytary in a patient with Parkinson's disease?  

The manufacturer has a suggested conversion table in the package insert:  https://rytary.com - pi.pdf (impaxlabs.com) However, many patients do not respond well using this table, so be prepared to make adjustments over the next few days. I find the duration of action varies from 4 to 8 h...