Pain killers a year post-op

Hi all!  I've been so busy with school and work that I just don't check in much anymore.  Anyway, good news is I'll be a year post-op in a couple months and I've lost over 100 lbs!  I still have a little ways to go until goal but I'm getting there.

So here's my question, I'm wondering about the effectiveness of painkillers after surgery.  I have injured my back and am currently taking narcotic pain killers plus a muscle relaxer.  They are supposed to last 6-8 hours, but here's the thing.  I find that they start working very fast and I feel great for awhile.  But the loopiness wears off after an hour and the pain comes back within 3-4 hours.  I'm wondering, is there any way that it's wearing off a lot faster than it should because of my sleeve?

The main reason I'm wondering this is because I noticed a similar effect with alcohol.  I don't drink much, but  after half a glass of wine, I'm pretty tipsy but then it wears off very fast, too. I thought maybe there's a correlation between the two.  Any ideas? 

I notice this with booze, too. One drink and I'm nice and drunk and the next minute (so it seems anyway), I'm sober.

Take you pain killer after eating some protein. That will slow down the digestion some and give it a chance to fully absorb into your system. I agree with the alcohol so I just keep drinking. Takes care of it wearing off to fast.

I can take one every four hours or two every six... I always opt for the one I figure if it wears off in three I can wait an about hour in pain unlike if the two wear of in four now I got two hours to wait... Can you half your pills and take them every three hours?

 I'll be 4 weeks post-op on Monday and I'm wondering the same thing with my ambien. I've always slept through the night when I take it. Since surgery, I have no problem falling asleep but wake up 3 hours later. I'm wondering if it just leaves my system quicker since being sleeved.