A 2011 study in rats claims caffeine and NSAIDs

Once the source of the hangover headache was located, the researchers then set about figuring out how to get rid of the pesky things, using known headache blockers. Turns out the combination of caffeine and over-the-counter inflammatory drugs (i.e., NSAIDs – things like aspirin and ibuprofen) were best at blocking the head-pounding effects of the acetate.