What can happen if I drink more than 3 Java Monsters a day?

I just noticed now noticed that on bottles of Java Monsters, it says “limit 3 per day”. Because of problems I’ve been having with lethargy lately, I’ve been drinking more than 3 a day once or twice a week (no medical advice needed on the lethargy – I know what’s causing it). I was wondering what exactly can happen if you over-consume them.

Edit: Forgot an important tid-bit. I’m taking Ritalin, about 10–15mg a day.