I don't drink any more but those 5-hour Energy Extra's are how to gnash your teeth and feel great. I use 2 at a time. Long hours at the grind and I do pay for it later. But I know the outcome and plan ahead for down time.
Expanding on Alvino's observation, the only reason you'd mix the two is trying to over come the downer effect alcohol has. If you manage to do that with the energy drink mixed in, you'll still be impaired and stuck in stupid. Gals don't like that sort of sot.
Besides the one thing everone has missed here. The stimulant effects of the energy drink mixed in can lull you in to thinking you can have more to drink.
Does alcohol poisioning come to mind? It can do brain damage or at the worst KILL your young ass.
Food for thought...