I have severe peripheral neuropathy.
I take lyrica, 200 mg. 3x plus an extra at bedtime. Gabapentin 600mg. 3x. Essentially, "maxxed out" on both of them. I also take vicodin, about 1-1/2 hour before bedtime.

Recently, I tried something different with my doctor. We weaned off both the lyrica and gabapentin while starting on the Fentanyl Patch. (synthentic morphine.) Once weaned off of those two, the pain was terrible while on 25 mcg/hour patch. I had to start taking some low dosages of lyrica and gabapentin. Then my doctor took me off of the Fentanyl Patch, and started me on MS Contin. (morphine sulfate - 30 mg.) up to 3x. Still pain was so severe that I stopped it and went back on my regular dose of lyrica and gabapentin.
I go to a monthly "Pain Support Group". Our speaker was a Pharmacist who has specialize in Pain Medicine.
Long story short, Morphine, Fentanyl, Oxycontin, all "opioids" do NOT work for nerve pain.
As a matter of fact, they make it worse.

(When I came off the trial of fentanly and morphine, which was almost 7 weeks, I couldn't understand why my pain was worse, even though I was back up to my normal dosage.)

He told me that although the vicodin is in that same catagory, and it works for me, I should keep using it for breakthough pain and at bedtime.

Bottom Line, Opioids will make your pain worse.
(They cause your nerve receptors to increase, which will make you feel more pain.)

Hope this helps some of you folks.