Caffeine is a common drug found in coffee, tea, colas, and many other over-the-counter analgesics. 100 mg to 150 mg of caffeine are found in one cup of coffee, however, it takes 250 mg of caffeine for caffeine Intoxication to occur. Restlessness, nervousness, excitement, insomnia, diuresis, muscle spasms, wandering thoughts or speech, tachycardia or arrhythmia, inexhaustibility, psychomotor agitation, gastrointestinal disturbance, and flushed face are all symptoms of caffeine intoxication. When several of these symptoms are combined together, they produce difficulty for the individual in functioning.