The US Food and Drug Administration (FDA) has approved istradefylline (Nourianz, Kyowa Kirin) tablets as add-on treatment to levodopa/carbidopa in adults with Parkinson’s disease (PD) experiencing “off” episodes.
Istradefylline is a selective adenosine A2A receptor antagonist.
Its effectiveness in treating “off” episodes in patients with PD taking levodopa/carbidopa was shown in four 12-week, placebo-controlled clinical studies that included a total of 1143 participants.
In all four studies, addition of istradefylline led to a statistically significant decrease from baseline in daily “off” time relative to placebo add-on, the FDA said in a news release.
The most common adverse reactions observed in patients taking istradefylline were dyskinesia, dizziness, constipation, nausea, hallucination, and insomnia. Patients should be monitored for development of dyskinesia or exacerbation of existing dyskinesia. If hallucinations, psychotic behavior, or impulsive/compulsive behavior occurs, consider reducing the dose or stopping the drug, the FDA advises.
Use of istradefylline in pregnancy is not recommended and women of childbearing potential should be advised to use contraception during treatment.
According to the National Institutes of Health, PD is the second most common neurodegenerative disorder in the United States after Alzheimer’s disease. An estimated 50,000 Americans are diagnosed with PD each year, and about 1 million Americans have the condition.