Your most likely crashing from the coffee. Coffee is a temporary boost, one of the w/d signs from opiates is anxiety, so i dont think coffee is such a great idea.
I had the same issue when I first started. I HAD to have a nap in the middle of the day. No questions. I started out on 8mgs once a day.
I still take that dose, but no longer have the sleepiness, at least not like in the beginning.
Talk to the doctor about lessening the dose or splitting it up, ie. once in the morning, once at night or whatever.
It took about a month to get used to the medicine. Another thing I should add is that when I was using, I would sleep 12 hours a night minimum. When in w/d's I could expect maybe an hour.
Depending on your husbands use, it could be his body's reaction to becoming stable. This is based on my experience.
my husband who is also on suboxone is having the same problem ... he gets up has a couple cups of coffee and then has to take a nap for abt 2 hrs... he crashes abt 2-3 hours or less of waking. the dr says its adjusting to the sub....
It may not be the coffee. It may be your dose needs to be adjusted. Perhaps you should call the doctor. What dose are you on?