Caffeine Intoxication: Unregulated, Over-the-Counter Sale of Potentially Deadly Supplements.

Caffeine is an integral part of beverages, food, and medications. Severe intoxication of caffeine is rare, and reports are even scarcer. However, over-the-counter, unregulated sale of performance-enhancing compounds, such as caffeine, turns high-dose consumption into a real concern. Severe intoxication may be fatal, usually by malignant cardiac arrhythmia. We report a case of a 23-year-old university student who accidentally consumed about 100 times the amount present in an expresso of anhydrous caffeine.