the Fatwa Department Research Committee - chaired by Sheikh `Abd al-Wahhâb al-Turayrî
It is known that caffeine is a mild stimulant. In this way it can rightly be called a "drug". However, that does not mean that it is an intoxicant. An intoxicant is a substance that blurs or distorts the rational faculties of the person who takes it.
Assuming that pure caffiene could intoxicate in very large quantities, it would still be the case that in order for a food or drink containing caffiene to be counted as an intoxicant, it would have to cause intoxication if consumed in quantities that a human being could reasonably ingest within a timeframe that would allow intoxication to take place.
This is not the case for chocolate, cola, coffee, or tea.
And Allah knows best.
Source: Islam Today