I take caffeine tablets for my fibromyalgia fatigue. I haven't noticed any problem with them so since you need them for medicinal purposes, why not try them and see.
Not something I'd normally recommend to everybody, but in your situation, like mine, sometimes we have to find a middle ground.
As you probably know, they're available over the counter in the drugstore and there's lots of brands including store brands. No Doz, Lucidex, Vivarin, etc.