Hi Chicano and welcome to the site.
I have been on Avonex a little over a year and taking alpha lipoic acid for about 9 months at 1200 mg/day. I personally think it does wonders for the numbness, burning and tingling.
site has some detailed scientific information about ALA, but doesn't address MS or the interferons.
I have no idea if it would act counter to the Rebif or the Avonex. I seriously doubt if there's information about this, but we could ask our neuros I guess.
Nice to hear you're doing well.