I am so sorry I misread what you wrote. I know that sleep is different for everyone and how they respond. I hope you find something that helps with sleep. Please forgive me if I offended you.

@vi30295 re how long for carbidopa/levadopa. I’m considered early Parkinsonism, and for me after about two weeks I noticed tremor improvement, and after three weeks I noticed I was sleeping better which I was not expecting. I have no idea if that improvement is related to the drug , need others to weigh in. Two of the family members I have cared for experienced “sundowning”, so I know how exhausted you must be. Search for sundowners both within and outside of this Parkinsons topic. My experience is dated back to 2009, but I was lucky in that the trazodone with melatonin worked for us. Maybe something newer has come out. I am so sorry your family is going through this.

Wow! Who's letting you (prescribimg) try all the different meds??? Sounds like the doctor is out on a limb, just fishing around.
I have had sleepless issues off and on for many years, but lately it had become a constant.....some nights about 5 hours (!!!), many many zero hours of sleep per night. My average over 60+ days was two hours. Not enough to reach REM sleep. not enough to turn off my busy braiin, which is all I could call it. Ask the patient: what does he HEAR when trying to sleep, and what does he THINK..... also search "Earworm" before you ask...I've had so-called medically trained people who merely thought I was psychotic (really 🙁 and that led to BAD things).
When things became impossible, I was sleep-deprived, nauseous, vomiting, hallucinating when closing my eyes, had aan on-going earworm, was constantly semi-awake: fuzzy vision, mixed up thought processing, inability to concentrate or multitask, and plenty more. The solution was actually very simple. While a simple dose of 20 mg of melatonin once worked, now results were too varied. When I was put on Quetipiene 25 mg 3/day with 200 mg at night (Yes, that's overkill, but not mine), plus 10 mg Melatonin at suppertime, Clonazepam 0.5 mg AM and bedtime, Cymbalta 60 mg at breakfast and suppertime....I slept. I'm still waiting for my next neurologist's appt so I can get mediation on the Q...i know the nighttime dose is too high, or rather, higher Than Necessary. I've been cutting 200 mg pills into quarters (50 mg) at bedtime, when prescribed dose is 200, and all the noise will stop, and I can fall asleep. That's what's been keeping me awake: noise. Buzzing, talking, planning, worrying, re-living events, hearing pieces of songs. All the other meds were already being taken, so it must be the Seroquel (Quetiapine). I'm also going to ask about cutting out one daytime dose, to further relieve my feeling of daytime dizziness, sleepiness. Sorry for the long reply. The Seroquel took One Day to get me sleeping 8 hours a night and continues to do so 3 weeks later. I suspect, but can't verify that I was given an initial high dose, before going to the day/night dosage. Good luck to all. (and Cd/Ld never caused sleep disturbances, just for the record)