As I was saying, in the case of energy drinks or carbonated drinks, the possibility of acute intoxication is very low. Such intoxication is generally caused by consuming caffeine-containing medications. This phenomenon is rarely observed in children.
However, the poison control centre's reports indicate that the number of cases has increased substantially since 2004. There were four reports of intoxication caused by energy drink ingestion in 2004, and 104 such cases were reported in 2008. The reported effects were fairly mild, such as palpitations, nausea, and so on.
The issue at hand is caffeine's chronic toxicity, and I was telling you earlier about caffeinism, which develops through caffeine consumption. Its symptoms include irritability, shaking, muscle twitching, palpitations, hot flashes, and other effects associated with long-term caffeine overconsumption.
Another related issue is caffeine withdrawal syndrome, which is the exact opposite of caffeinism and is associated with fatigue, depression, poor concentration, and especially with headaches that ensue when a person stops consuming caffeine. These effects are usually experienced in the 12- to 24-hour period after people cease consuming caffeine and are remedied by caffeine ingestion.
So, there are two different phenomena related to caffeine use: caffeinism and caffeine withdrawal syndrome. The latter can last for a few days.