Energy drinks must be taken properly because the ingredients used in it are powerful enough to affect your system & body.
Ingredients used in these drinks can affect your heartbeat and blood pressure.
Don't ever try to make energy drink an alternative for the lost water in the system while doing exercise because the caffeine in the energy drink can leave a dehydrating effect on your body.
The most important point is that you should never combine energy drinks with alcohol because energy drink is a stimulant while alcohol is a depressant. You can imagine yourself the contrasting effect that this combination can bring in your system.