Conversation so far:
Is Red Bull bad for you?
Despite these increases, moderate and occasional intake of Red Bull is unlikely to cause serious heart problems in healthy adults.
Can Red Bull kill you?
And it can kill you. The WHO study also reports that adults who consume energy drinks may be increasing their risk of hypertension and type 2 diabetes (caffeine reduces insulin sensitivity)
How much Red Bull can you drink in a day?
Per multiple references a standard Red Bull contains 80 mg of caffeine (but most producers would make different products). A daily long term limit for caffeine ingestion is 400 mg per day (so five cans is at that limit), but that's related to side effects, not risk of death.

Question: What is taurine
Self-contained rewrite: What is taurine?