Brian, Deb is addicted to caffeine; like Esther, if she doesn’t get some, she gets headaches. OTOH, she can get by with what are (IMHO) micro-doses, like a can of Diet Coke. Me, I can drink a can of cola and fall asleep (ask me how I know). But too much coffee does a number on my stomach, so I do 200mg caffeine pills. Fast, easy, simple. If you go this route invest in generic caffeine pills from your local CVS or Rite-Aid, it cuts down costs considerably; also, look for boxes with pill bottles rather than blister packs (although the latter are easier to take along for emergencies or road trips).
I used to be on a 400mg/day habit, now I’m down to 200mg. Okay, 200mg plus a mug or two of black tea. And sometimes a mug of coffee with a lot of creamer.