back before Pepcid (Famotidine) became an over-the-counter drug for acid problems, my doctor gave me a prescription for it as a hangover preventative. (I was getting a headache after 2-3 beers, without getting drunk.)
He explained that the executives at (my doctor knew a couple) were using the drug when they went out to eat and drink as a heartburn preventative, but started noticing that symptoms of hangovers were much reduced. They could still get drunk, but with fewer problems. As he explained it, they had quite a debate over whether to advertise this, and concluded that it would not do offer people 'officially' a way to over-indulge...so they were content to make a fortune on it's standard claims.

I have used it for years, and I think it does help...when I remember to take it BEFORE I drink! I do not drink a lot these days, so I am not the best test case, but......

If you test this, use it sanely...