They are not the same family.

Valium is Diazepam which is for anxiety, etc.

From wikipedia: Diazepam is mainly used to treat anxiety, insomnia, and symptoms of acute alcohol withdrawal. It is also used as a premedication for inducing sedation, anxiolysis or amnesia before certain medical procedures

It is known also as a "benzo" which is short for benzodiazepines (also in this class are things like xanax, etc.

Vicodins (or norcos, lorabs, same class as percocets and oxycotin) aare hydrocodone and don't really fix the hangover as much as cover it up with the typical euphoric feeling painkillers deliver. They are typically easier to get on the street, or from pretty much any urgent care that has an on-site pharmacy and likes cash, and less likely to make you sleepy which is why I occasionally use them for work hangover days. However, as the vicodin wears off, the hangover can come back to life.

oxycodone (percocets) and alcohol are a bad combo in my book, like vicodin and alcohol, mostly because it makes you drunker. Typically hydrocodone is a tad harsh on the stomach (not unbearably so, but slight nausea for some.) The only time I started drinking within a few hours of taken a norco, I threw it all up about 5 minutes later. Pretty bummer. I don't know many who prefer that exilir, but I know a lot of people who like the xanax alcohol combo or adderall alcohol. Don't know why for the prior, just seems like a lot of blacked out numbness to me.