I've been on clonazepam for 18 years for a variety of neurological issues. Perhaps some of my experiences may be of benefit. Caveat: All bodies are different.

My late morning/noon dose will do one of two things on any random day: Either I become more energised and focused, hence carrying on with my chores without feeling scattered and fatigued, OR I crash and burn and take a nap. Never predictable.

The evening dose, in contrast, has about a ninety percent predictability in its affect when I take it 45 to 90 minutes before going to bed. Often, a light snack is helpful. Then, my next five hours of sleep is usually tolerable with some breakthrough in restless leg/PLMD.

Clonazepam does have a mild antihistamine effect...that can and does give me moderate dry mouth and eyes.

Years ago when this med became available as a generic, I had a heck of a time staying stabilised. I went back to brand name for a while (Klonopin), then tried a generic by Teva and have been ok ever since with that. My doctor reported that many people had difficulty with generic equivalents of Klonopin. Your mileage may vary.

You and I have obviously different neurological hassles. However, the time I experienced industrial lead poisoning I got to see (after the fact) how this med performed on a central nervous system with demyelinating issues. During that period almost anything could, and did, happen. Still, it kept me stabilised enough to sort out what was going on and take positive action before too much damage was done.

Summation: Try that bedtime dose with more time in your system before you land...maybe with a bland snack?

Chat up your doctor and/or pharmacist about generic vs. brand?

Congrats on quitting smoking and I repeat what's already been said: your body is in a system-wide change from this alone and you're bound to experience some unpredictability.

And Mrsd down in the Medications forum could probably shed some light on this, too. She's a sharp one.

Best, Jeff