General Information

Nourianz (istradefylline) is an Adenosine A2A receptor antagonist.

Nourianz is specifically indicated as adjunctive treatment to levodopa/carbidopa in adult patients with Parkinson’s disease (PD) experiencing “off” episodes.

Nourianz is supplied as a tablet for oral administration. The recommended dosage of Nourianz is 20 mg administered orally once daily. The dosage may be increased to a maximum of 40 mg once daily, based on individual need and tolerability. Initial dose titration is not required. Nourianz can be taken with or without food.

Mechanism of Action

Nourianz (istradefylline) is an Adenosine A2A receptor antagonist. The exact mechanism by which istradefylline exerts it's effects on Parkinson's disease is unknown.

Side Effects

Adverse effects associated with the use of Nourianz may include, but are not limited to, the following: 

• insomnia
• dyskinesia
• dizziness
• constipation
• nausea
• hallucination

Clinical Trial Results

The FDA approval of Nourianz was based on four randomized, multicenter, double blind, 12-week, placebo-controlled studies.  The studies enrolled patients with a mean duration of Parkinson’s disease of 9 years (range: 1 month to 37 years) that were Hoehn and Yahr Stage II to IV, experiencing at least 2 hours (mean approximately 6 hours) of “off” time per day, and were treated with levodopa for at least one year, with stable dosage for at least 4 weeks before screening. The primary efficacy endpoint was the change from baseline in the daily awake percentage of “off” time, or the change from baseline in total daily “off” time, based on 24-hour diaries completed by patients. Study 1 was conducted in the U.S. and Canada, and Study 2 was conducted in the U.S. In these studies, patients were randomized to once-daily treatment with Nourianz 20 mg, 40 mg, or placebo. Patients treated with Nourianz 20 mg or Nourianz 40 mg once daily experienced a statistically significant decrease from baseline in percentage of daily awake “off” time, compared with patients on placebo. Study 3 and Study 4 were conducted in Japan. In these studies, patients were randomized equally to treatment with Nourianz 20 mg, 40 mg, or placebo. Patients treated with Nourianz 20 mg or Nourianz 40 mg once daily experienced a statistically significant decrease from baseline in “off” time compared with patients on placebo.