The limits of coffee

I'm starting to wonder if there's a point where coffee just doesn't work; that is, it doesn't work in any good way. It still dries me out like crazy and messes with my gut. But I don't feel any more awake or alert.
So far, the Neurontin/Gabapentin has made me feel pretty drowsy, lasting until morning even. And, come to think of it, pretty dried out. It's been hit or miss helping me sleep.
It doesn't help that we're just entering into a heat wave (the same heat wave the rest of the country has been in for a long time) and there's no air conditioning. I need to pick up another fan today.
It will be nice to spend a night on the coast this weekend. It should be a little cooler, at least.