Newly medicating 6yr old for Tourette's

[5ofus]

Hey there. Shouting out into the dark, here.
My son is 6. He was diagnosed with Tourette's, OCD, Spasticity, anxiety, and ADHD about a year ago. We've just begun a medication in hopes of treating or minimizing the Tourette's symptoms, as they have become disruptive to his teachers and classmates.
I have read and read and read. I have educated, advocated, and empathized. My son understands his disorder. He knows how to respond to inquiries and requests to "stop". We role-play. He is highly intelligent, witty, vivacious, energetic, highly empathic and sensitive, and has a wicked sense of humor.
The medication we have started him on is dimming his "light". He is lethargic and listless. Sullen and apathetic. He speaks slowly and is almost inaudible. His neurologist began him on 1 mg of Intuniv. I've read a lot about the drug and I know that it is an ADHD medication. However, the purpose of the prescription was to mitigate the tics, which I understand is almost a tertiary use of the prescription. I don't know if there is an adjustment period where he will build up a tolerance to the drowsy-like (but beyond) reaction my son is having. He just isn't my child. I don't know the kid I see. It breaks my heart and makes me question medicating him at all. I don't know any other parents of Tourette's kids. I don't know who to talk to aside from my spouse and my child's doctors. I need a village.
Help.