A Colorado high school has banned a newly-released energy drink after six students reported "symptoms including shortness of breath, heart palpitations and nausea." Interestingly, convenience stores near the high school have also stopped selling the energy drink, Spike Shooter.

Tim Patterson, chief executive of Colorado Springs-based Biotest Laboratories, which produces Spike Shooter, said the drink isn't meant for anyone under 18. "I don't want these kids consuming the product," Patterson said. "That's not my target market."

Funny. The 7 February press release from the company notes from the very same Mr. Patterson:

"We are thrilled that SPIKE is resonating in the hardcore category because the hardcore consumer is comprised of the largest and most-committed demographic makeup in the entire energy-drink category -- 16 to 29 year-old males and females," Patterson says. "Like our commercial says, 'Once you take a sip of SPIKE, you'll never go back.'"

16...18...what's the difference, right?

The launch of Spike Shooter was highly anticipated among energy drink enthusiasts because a can contains 300 mg of caffeine, about 6 times that of the average 12 oz. cola. In their defense, the Spike Shooter label recommends starting with only half a can (but then the website notes, "Spike is so potent, the label warns newbies to take it slow...but the flavor's so good you'll want to slam the whole can.")

Caffeine, of course, has been the most widely used stimulant throughout world history. However, it has the potential to cause adverse cardiovascular effects in sensitive individuals, especially those predisposed to cardiac arrhythmias (disturbances in coordination of heart rhythm) or abrupt increases in blood pressure. Caffeine is particularly dangerous when combined with drugs called sympathomimetics, agents whose effects resemble that of norepinephrine or epinephrine (noradrenaline or adrenaline for readers in the commonwealth countries).

Ephedrine is one example of a sympathomimetic, or agent that mimics the effect of the neurotransmitters of the sympathetic autonomic nervous system. It is particularly dangerous when combined with caffeine and this was the likely cause of deaths associated with ephedrine-containing weight loss supplements that led to the US ban on ephedrine.

Interestingly, caffeine is listed by the US FDA on their "generally recognized as safe," or GRAS list. However, Section 182.1180 of the FDA GRAS list indicates the following:

(a) Product. Caffeine.
(b) Tolerance. 0.02 percent.
(c) Limitations, restrictions, or explanation. This substance is
generally recognized as safe when used in cola-type beverages in
accordance with good manufacturing practice.

That means that cola drinks are limited to 71 mg of caffeine per 12 oz/355 mL serving. Caffeinated colas are usually well within this value, even when fountain colas were tested (where you might expect great variability based on the syrup mix).

Energy drinks get around this federal limitation by being declared as dietary supplements (and by being largely insipid rather than cola flavored). There is some confusion as to the regulations surrounding energy drinks and the Center for Science in the Public Interest has petitioned the FDA to define and regulate these drinks more precisely.

But, then again, most of these science blogs, grant applications, and research manuscripts are written by caffeine-fueled docs and scientists who primarily obtain their caffeine from coffee. Coffee drinks vary widely in their caffeine content but the London-based International Coffee Organization notes that a 5-ounce serving of coffee contains 80 to 115 mg of caffeine. It's been a long time since I had heart palpitations or dizziness from coffee. And the first coffee I ever drank was probably a weak, pre-Starbucks, McDonald's coffee - but in my caffeine-naive days, I wonder how a 300 mg Spike of caffeine might make me feel.

I'll also be looking forward to comment on this episode at Justin's Energy Drink Ratings - although he is based in Colorado, even he hasn't yet rated Spike Shooter.