I read a recent report of Monster energy drinks causing five deaths over the last year from an excess of caffeine intake but I didn't realize is that 5-Hour Energy is blamed for 13 deaths over the last four years plus an additional 17 reports of heart attacks, convulsions and, in one case, a spontaneous abortion. The manufacturer doesn't report the caffeine level of one "shot," but Consumer Reports says that it's 215 mg.
Caffeine levels in energy drinks range from 160 mg to 500 mg per serving.
I have reduced my caffeine intake to 93 mg per day (two cans of soft drinks) mostly to reduce my blood pressure.
It seems that caffeine in high doses may not be good for you, especially if you want to live long and prosper.