Whenever you trigger one change in the brain, it is important to consider how this impacts other parts of the brain too.
In particular, when you alter one neurotransmitter, this will almost always result in others changing too. When you reduce adenosine, this wakes the brain up and it increases activity across all of your connectome.
The brain responds to this by assuming that something important must be happening and therefore it will increase the production of dopamine, norepinephrine and other neurotransmitters associated with focus and attention.
This helps us concentrate and get more done.