It's possible. Any strong medication or combination of them can cause a mental fog. Are all these medications prescribed by the same doctor? If not, all your doctors need to know every medication you are on so they don't over-prescribe. If the side-effects are really problematic, you should talk to your doctor about it and maybe there would be a better combination for you.

Do they know the cause of your peripheral neuropathy?

Have you tried going to a pain management specialist or clinic? I've heard people say they can really help, especially with pain that has previously been difficult to manage. Do a search for something like that in your area. Maybe they can help.

I've heard that electrical stimulation of the nerves involved in neuropathic pain generation may significantly control the pain symptoms. You might want to do some research about that, if you haven't already.

Also, alternative medicine, such as acupuncture combined with other therapies has also been shown to be effective for many people. Even if you are skeptical that alternative therapies are useful, what do you really have to loose by trying? Just a suggestion.

I hope you can find some relief from your pain. Good luck.