Kyowa Kirin’s istradefylline (Nourianz) is now available in the United States, according to the company. Istradefylline is an adenosine receptor antagonist indicated as adjunctive treatment to levodopa/carbidopa in adult patients with Parkinson’s disease (PD) that are experiencing “off” episodes.1 During these "off" episodes, a patient’s medications are not working well and symptoms, such as tremors and difficulty walking, are increased.2

Officials with the FDA approved istradefylline in August 2019, based on findings from randomized, multicenter, double-blind, placebo-controlled trials in patients with PD taking a stable dose of levodopa/carbidopa with or without other PD medications. In clinical studies, use of istradefylline as adjunctive treatment to levodopa/carbidopa in adult patients with PD experiencing “off” episodes was associated with a decrease in “off” time and an increase in “on” time without troublesome dyskinesia.2 

The most common adverse reactions with an incidence ≥5% and occurring more frequently than with placebo were dyskinesia, dizziness, constipation, nausea, hallucination, and insomnia.1,2

“Options such as Nourianz are a step forward in treating ‘off’ episodes, which can be troublesome and isolating for people with Parkinson's and their families,” said Rachel Dolhun, MD, Vice President, Medical Communications at The Michael J. Fox Foundation.1 “We encourage patients to speak with their health care providers if they are experiencing ‘off’ episodes.”

There are approximately 1 million people in the U.S. with PD and about 60,000 Americans are diagnosed each year. Within 5 years of initiating levodopa/carbidopa, approximately 50% of people may experience “off” episodes in which motor symptoms occur between treatment doses.1

  1. Kyowa Kirin Announces NOURIANZ™ (Istradefylline) Now Available in the U.S. for Treatment of Parkinson’s Disease “Off” Episodes [news release]. Bedminster, NJ; October 15, 2019: Kyowa Kirin. Accessed October 15, 2019. 
  2. Murphy J. FDA Approves Istradefylline Tablets for Treating Off-Episodes in Parkinson Disease. Pharmacy Times [online]. Published August 28, 2019. Accessed October 16, 2019.