When I married my 1st husband, he had a back injury from being a high rise window cleaner. He had back surgery that didn't work & was using booze to control his pain. (He was also an alcoholic). Long story short, I decided to do some research for him & I know it was my higher power working...I found a doctor who specialized in pain management & also happened to be a recovering alcoholic. My husband went to see him & was sober for 8 years after that. Also, a part of the program was for spouses & families & it was extremely helpful in dealing with someone in pain 24/7.
I know you have your plate full, but I also think that sometimes we are "partners" in a marriage & that his request is valid. However, I do wonder why you have never gone to the doctor with him before? If he is asking for your help & advice, I think it would be valuable for you to go to the doctor with him & discuss the options.
Of course, this is what people do in a "healthy" relationship. And, unfortunately, pain can also wreck a marriage. I've been dealing with some pain issues personally & it is taking it's toll on me.
As someone else said....there are addicts & then there are people who use pain meds as a way to keep living.
Lynne