A 69-year-old man with a 5-year history of Parkinson's disease comes to the clinic for follow-up. He has tremors that improve soon after taking his medications, but then worsen over time. There was some improvement after his last appointment, during which his drug regimen of levodopa/carbidopa and entacapone was adjusted. While he still responds to levodopa, he has had increasing motor fluctuations and his medications are limited by orthostatic hypotension. He also reports occasional disorientation. Physical examination shows orthostatic hypotension and dyskinesia. Neurocognitive assessment is compatible with mild cognitive impairment. Which of the following is true regarding his further management?