Rasagiline (Azilect - Teva), a monoamine oxidase-type B (MAO-B) inhibitor, was recently approved by the FDA for once-daily oral treatment of Parkinson's disease (PD). It can be taken alone for treatment of early disease or with levodopa/carbidopa (Sinemet, and others) for advanced disease. Selegiline (Eldepryl, and others), the first MAO-B inhibitor marketed in the US, has been available since 1988; a new lower-dose disintegrating tablet (Zelapar) was recently approved.

A selective serotonin reuptake inhibitor (SSRI) is generally used for initial treatment of major depressive disorder (MDD). A serotonin-norepinephrine reuptake inhibitor (SNRI), bupropion (Wellbutrin SR, and others), and mirtazapine (Remeron, and others) are reasonable alternatives. Improvement in symptoms can occur within the first two weeks of treatment with these drugs, but a substantial benefit may not be achieved for 4-8 weeks.

View the Comparison Table: Drugs for Parkinson's Disease

The motor symptoms of Parkinson's disease (PD) are caused primarily by degeneration of dopaminergic neurons in the substantia nigra. The nonmotor symptoms of the disease are thought to be caused by degeneration of other neurotransmitter systems. No disease-modifying drugs are available for treatment of PD.