Only if they're Campagnolo downtube shifters shimmed to fit on the stem, AdventureManCO-style.

Given that your return ride may involve stumbling over into the lawn of a neighbor - preferably the one that will provide the maximum amount of embarrassment to conclude your evening with - make sure your Campagnolo downtu stem shifters are paired with polished crank dustcaps. Keep it classy and all that, you know.

-Kurt