^This. Why would you take a cocktail of downers anyway? I don't think it would make you the life of the party. You'd probably be the guy who passes out right away and has his face scibbled on with a magic marker and his eyebrows shaved off. Yes it's dangerous, and pointless!
Be careful of your tolerance before you decide to do anything rash. Unless you're lowering your doses and have certain knowledge of your tolerance to these drugs I wouldn't fuck with it.