Caffeine is a xanthine alkaloid with a psychostimulant effect mediated by its antagonistic action at adenosine A2A receptors. Its pharmacological targets are primarily striatal A2A-D2 receptor heteromers. However, as a non-selective adenosine receptor antagonist, it also blocks presynaptic A1 receptors, leading to its monoaminergic action. Depending on the concentration it may interact with GABA-ergic neurotransmission and act at ryanodine receptors as an agonist. Neuropsychopharmacological profile of caffeine also determines its neuroprotective effect, synergistic effect with antidepressants, but also its undesirable and potentially dangerous effects in combination with other psychostimulants.

Key words: caffeine – adenosine – dopamine – caffeine intoxication – caffeine withdrawal – caffeine use disorder – psychostimulants