Yes, stress does affect the way the medication works. It is likely to be because of the effects of stress on the gut, and the way the vagus nerve acts as a big super highway between the body and the brain. Medication is only absorbed in a section of the small intestine so anything that affects the vagus nerve and the gut will disrupt the absorption of medication. We have found that a daily dose of aloe vera juice soothes the gut ( and keeps the vagus nerve happy) and this has smoothed out my husband's responses to stress.

Melatonin can help with sleep. Sleeping pills are awful, but melatonin is natural.

I am on sinemet, which is the carbidopa/L.
As long as I get my 3 in for day I am generally ok. If I am going to have negative responses it will be early or late in day. Then I nap a lot or just put my head in sand cause nothing I am going to do will be right. Even my hand writing.

Ps. I find that lack of sleep is the first sign that a panic period is coming. I sleep in a recliner if I lay in bed it seems to make me worry and I cry and I panic. So I begin to associate sleep with panic. Vicious cycle.

Jim, I agree. If I'm not stressed I'm almost symptom free. And I can manage what I do have better. If I'm in "panic" I can hardly move or breathe. Ive just gotten out of one of my worst periods of anxiety . And it was relieved by the timely and totally unexpected outreach by a very old friend . You never where Gods lifeboat come or in what form . But I try to be grateful for all my blessings. Hug