The Food and Drug Administration on Aug. 27 approved Nourianz (istradefylline) tablets as an add-on treatment to levodopa/carbidopa in adult patients with Parkinson’s disease experiencing off episodes. During off episodes, patients’ medications do not work well, and symptoms such as tremor and difficulty walking increase.
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The effectiveness of Nourianz for this indication was shown in four 12-week placebo-controlled clinical studies that included 1,143 participants. In all four studies, patients treated with Nourianz experienced a statistically significant decrease from baseline in daily off time, compared with patients who received placebo.
The most common adverse reactions to istradefylline with an incidence of 5% or greater and occurring more frequently than with placebo were dyskinesia (15%, 17%, and 8%, for Nourianz 20 mg, 40 mg, and placebo, respectively), dizziness (3%, 6%, and 4%), constipation (5%, 6%, and 3%), nausea (4%, 6%, and 5%), hallucination (2%, 6%, and 3%), and insomnia (1%, 6%, and 4%). In clinical trials, 1% of patients treated with Nourianz 20 mg or 40 mg discontinued treatment because of dyskinesia, compared with no patients who received placebo.
In addition,one patient treated with Nourianz 40 mg experienced impulse control disorder, compared with no patients who received Nourianz 20 mg or placebo.
If hallucinations, psychotic behavior, or impulsive or compulsive behavior occurs, a dosage reduction or stoppage should be considered, according to the FDA. Use of Nourianz during pregnancy is not recommended, and women of childbearing potential should be advised to use contraception during treatment.
The maximum recommended dosage in patients taking strong CYP3A4 inhibitors is 20 mg once daily, and clinicians should avoid use of Nourianz with strong CYP3A4 inducers.
Istradefylline is the first adenosine A2A receptor antagonist for use in Parkinson’s disease in the United States, and the drug provides patients with a novel nondopaminergic daily oral treatment option, according to a news release from Kyowa Kirin, the company that markets the drug.
Since 2013, istradefylline has been marketed at Nouriast in Japan, where it is indicated for the wearing-off phenomenon in patients with Parkinson’s disease who take preparations containing levodopa.