Rasagiline (N-propargyl-1-(R)-aminoindan) is a selective, irreversible monoamine oxidase B (MAO B) inhibitor, which has been developed as an anti-Parkinson drug and was sold as a mesylate salt under brand name AZILECT. AZILECT is indicated for the treatment of the signs and symptoms of idiopathic Parkinson’s disease (PD) as initial monotherapy and as adjunct therapy to levodopa. The effectiveness of AZILECT was demonstrated in patients with early Parkinson’s disease who were receiving AZILECT as monotherapy and who were not receiving any concomitant dopaminergic therapy. The effectiveness of AZILECT as adjunct therapy was demonstrated in patients with Parkinson’s disease who were treated with levodopa. PD is a progressive neurodegenerative, dopamine deficiency disorder. The main therapeutic strategies for PD treatment relies on dopamine precursors (levodopa), inhibition of dopamine metabolism (monoamine oxidase [MAO] B and catechol-O-methyl transferase inhibitors), and dopamine receptor agonists. In contrast to selegiline, rasagiline is not metabolized to potentially toxic amphetamine metabolites. The precise mechanisms of action of rasagiline is unknown. One mechanism is believed to be related to its MAO-B inhibitory activity, which causes an increase in extracellular levels of dopamine in the striatum.