Parkinson’s Disease (PD) is a neurodegenerative disease involving degeneration of dopaminergic
neurons of the nigrostriatal pathways. Over the past decades, most of the medications for the
treatment of PD patients have been used to modulate dopamine concentrations in the basal ganglia.
This includes levodopa and its inhibitory metabolizing enzymes. In addition to modulating dopamine
concentrations in the brain, there are D2-like dopamine receptor agonists that mimic the action of dopamine
to compensate for the deficit in dopamine found in PD patients. Muscarinic antagonists’ drugs
are used rarely due to some side effects. Monoamine oxidase inhibitors are among the first in line, and
are considered popular drugs that reduce the metabolism of dopamine in PD patients. Furthermore, we
discussed in this review the existence of certain glutamate receptor antagonists for the treatment of
PD. Alternatively, we further discussed the potential therapeutic role of adenosine (2A) receptor antagonists,
such as tozadenant and istradefylline in the treatment of PD. We also discussed the important
role of serotonin1A receptor agonist, adrenergic autoreceptors (α2) antagonists and calcium
channel blockers in the treatment of PD. Finally, neurotrophic factors, such as glial cell line-derived
neurotrophic growth factor and brain-derived neurotrophic factor are considered the primary factors
for neuroprotection in PD.