The FDA has approved the monoamine oxidase type B (MAO-B) inhibitor safinamide (Xadago – US Worldmeds) as an adjunct to levodopa/carbidopa for management of "off" episodes in patients with Parkinson’s disease (PD). It is the first reversible MAO-B inhibitor to be approved for this indication. Selegiline (Eldepryl, and others) and rasagiline (Azilect, and generics), two irreversible MAO-B inhibitors, have been used alone and as adjuncts to levodopa/carbidopa for many years. Safinamide is not approved for use as monotherapy.

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.

The FDA has approved istradefylline (Nourianz — Kyowa Kirin), an oral adenosine A_2A receptor antagonist, for use as an adjunct to carbidopa/levodopa in adults with Parkinson's disease (PD) who experience "off" episodes. Istradefylline is the first adenosine A_2A receptor antagonist to be approved in the US; it has been available in Japan since 2013.

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.