Caffeine Pathophysiology

Caffeine has been used as a medicinal and recreational drug since before recorded history.

Caffeine has many effects in the body. The three most commonly documented effects are

1. adenosine receptor antagonism - causes high blood pressure, tremor, agitation, constriction of blood vessels, speeding of heart pacemaker cells
2. phosphodiesterase inhibition - causes activation of the central nervous system (CNS) and production of adrenaline and dopamine
3. enhanced intracellular calcium levels - causes increased intracellular calcium levels
4. increased intestinal secretions - causes diahorrea and abdominal cramps