I should mention that because buprenorphine is opiod-based, it can cause drowsiness and spacey-ness. Start with as small a dose as possible to deal with the pain without causing too much of a dopey reaction.
And do look into acupuncture if that's an option near you. It could also help with the constipation!
"To close your eyes will not ease another's pain." ~ Chinese Proverb
“We must not refuse to see with our eyes what they must endure with their bodies.” ~ Gretchen Wyler