The question appears to be motivated by headlines similar to this
Mixing large doses of both acetaminophen painkiller and caffeine may increase risk of liver damage
where it states
WASHINGTON, Sept. 26 2007 — Consuming large amounts of caffeine while taking acetaminophen, one of the most widely used painkillers in the United States, could potentially cause ...
Diet soda isn't inherently bad for you: http://examine.com/nutrition/is-diet-soda-bad-for-you/
It's hard to come up with any conclusive statements about caffeine; it is an incredibly well researched topic, but the immense social usage of it and creeping biases make it hard to pick a side on things outside of non-applied biochemistry.
The dosages of ...
It's nicely summarized in "Energy Drink Breakdown: What’s in a Red Bull, Anyway?":
Basically, Red Bull is a mix of sugar, caffeine, taurine and several B vitamins, all of which are well known for their energy-promoting qualities.
As far as I know, it's true for all energy drinks. So yes, they contain caffeine which is also the main ingredient of coffee ...