Istradefylline

Generic Name: istradefylline

Over-the-Counter (OTC)

Brand Names:

Nourianz

11 DESCRIPTION NOURIANZ contains istradefylline, an adenosine receptor antagonist, which has a xanthine derivative structure. The chemical name is ( E )-8-(3,4-dimethoxystyryl)-1,3-diethyl-7-methyl-3,7-dihydro-1 H -purine-2,6-dione. Its molecular formula is C 20 H 24 N 4 O 4 . The molecular weight is 384.43. Istradefylline has the following structural formula: Istradefylline is a light yellow-green crystalline powder. Istradefylline has a dissociation constant (p K a ) of 0.78.

Overview

11 DESCRIPTION NOURIANZ contains istradefylline, an adenosine receptor antagonist, which has a xanthine derivative structure. The chemical name is ( E )-8-(3,4-dimethoxystyryl)-1,3-diethyl-7-methyl-3,7-dihydro-1 H -purine-2,6-dione. Its molecular formula is C 20 H 24 N 4 O 4 . The molecular weight is 384.43. Istradefylline has the following structural formula: Istradefylline is a light yellow-green crystalline powder. Istradefylline has a dissociation constant (p K a ) of 0.78.

Uses

1 INDICATIONS AND USAGE NOURIANZ is indicated as adjunctive treatment to levodopa/carbidopa in adult patients with Parkinson's disease (PD) experiencing "off" episodes. NOURIANZ is an adenosine receptor antagonist indicated as adjunctive treatment to levodopa/carbidopa in adult patients with Parkinson's disease (PD) experiencing "off" episodes ( 1 ).

Dosage

2 DOSAGE AND ADMINISTRATION The recommended dosage is 20 mg orally once daily. The dosage may be increased to a maximum of 40 mg once daily ( 2.1 ). May be taken with or without food ( 2.1 ). Patients with hepatic impairment: Maximum recommended dosage with moderate hepatic impairment is 20 mg once daily; use of NOURIANZ in patients with severe hepatic impairment should be avoided ( 2.4 , 8.7 ). Patients who smoke 20 or more cigarettes per day (or the equivalent of another tobacco product): Recommended dosage is 40 mg once daily ( 2.5 , 8.8 ). 2.1 Dosing Information 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.

Side Effects

6 ADVERSE REACTIONS The following clinically significant adverse reactions are discussed in greater detail in other sections of the labeling: Dyskinesia [see Warnings and Precautions (5.1) ] Hallucinations / Psychotic Behavior [see Warnings and Precautions (5.2) ] Impulse Control / Compulsive Behaviors [see Warnings and Precautions (5.3) ] The most common adverse reactions (at least 5% and more frequent than placebo) were dyskinesia, dizziness, constipation, nausea, hallucination, and insomnia ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Kyowa Kirin Inc. at 1-844-768-3544 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Interactions

7 DRUG INTERACTIONS Strong CYP3A4 inhibitors: Recommended maximum dosage with concomitant use is 20 mg once daily ( 2.2 , 7.1 ). Strong CYP3A4 inducers: Avoid use ( 2.3 , 7.1 ). 7.1 Effect of Other Drugs on NOURIANZ Strong CYP3A4 Inhibitors Coadministration of NOURIANZ with a strong CYP3A4 inhibitor (ketoconazole) increased istradefylline AUC inf by 2.5-fold [see Clinical Pharmacology (12.3) ] . Therefore, the recommended maximum dosage of NOURIANZ in patients concomitantly using strong CYP3A4 inhibitors (e.g., itraconazole, ketoconazole, clarithromycin) is 20 mg once daily [see Dosage and Administration (2.2) ].

Warnings

5 WARNINGS AND PRECAUTIONS Dyskinesia: Monitor patients for dyskinesia or exacerbation of existing dyskinesia ( 5.1 ). Hallucinations / Psychotic Behavior: Consider dosage reduction or stopping NOURIANZ if occurs ( 5.2 ). Impulse Control / Compulsive Behaviors: Consider dosage reduction or stopping NOURIANZ if occurs ( 5.3 ). 5.1 Dyskinesia NOURIANZ in combination with levodopa may cause dyskinesia or exacerbate pre-existing dyskinesia. In controlled clinical trials (Studies 1, 2, 3, and 4) [see Clinical Studies (14) ] , the incidence of dyskinesia was 15% for NOURIANZ 20 mg, 17% for NOURIANZ 40 mg, and 8% for placebo, in combination with levodopa. One percent of patients treated with either NOURIANZ 20 mg or 40 mg discontinued treatment because of dyskinesia, compared to 0% for placebo. 4 CONTRAINDICATIONS None. None ( 4 ).

Pregnancy

8.1 Pregnancy Risk Summary There are no adequate data on the developmental risk associated with the use of NOURIANZ in pregnant women. In animal studies ( see Data ), oral administration of istradefylline during pregnancy resulted in teratogenicity (increased incidences of fetal structural abnormalities, embryofetal and offspring mortality and growth deficits) at clinically relevant exposures and in the absence of maternal toxicity.

Storage

16.2 Storage and Handling Store at 20°C to 25°C (68°F to 77°F); excursions permitted between 15°C and 30°C (59°F to 86°F) [see USP Controlled Room Temperature].

Frequently Asked Questions

What is Istradefylline used for?

1 INDICATIONS AND USAGE NOURIANZ is indicated as adjunctive treatment to levodopa/carbidopa in adult patients with Parkinson's disease (PD) experiencing "off" episodes. NOURIANZ is an adenosine receptor antagonist indicated as adjunctive treatment to levodopa/carbidopa in adult patients with Parkinson's disease (PD) experiencing "off" episodes ( 1 ).

What are the side effects of Istradefylline?

6 ADVERSE REACTIONS The following clinically significant adverse reactions are discussed in greater detail in other sections of the labeling: Dyskinesia [see Warnings and Precautions (5.1) ] Hallucinations / Psychotic Behavior [see Warnings and Precautions (5.2) ] Impulse Control / Compulsive Behaviors [see Warnings and Precautions (5.3) ] The most common adverse reactions (at least 5% and more frequent than placebo) were dyskinesia, dizziness, constipation, nausea, hallucination, and insomnia ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Kyowa Kirin Inc. at 1-844-768-3544 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Can I take Istradefylline during pregnancy?

8.1 Pregnancy Risk Summary There are no adequate data on the developmental risk associated with the use of NOURIANZ in pregnant women. In animal studies ( see Data ), oral administration of istradefylline during pregnancy resulted in teratogenicity (increased incidences of fetal structural abnormalities, embryofetal and offspring mortality and growth deficits) at clinically relevant exposures and in the absence of maternal toxicity.

What are the important warnings for Istradefylline?

5 WARNINGS AND PRECAUTIONS Dyskinesia: Monitor patients for dyskinesia or exacerbation of existing dyskinesia ( 5.1 ). Hallucinations / Psychotic Behavior: Consider dosage reduction or stopping NOURIANZ if occurs ( 5.2 ). Impulse Control / Compulsive Behaviors: Consider dosage reduction or stopping NOURIANZ if occurs ( 5.3 ). 5.1 Dyskinesia NOURIANZ in combination with levodopa may cause dyskinesia or exacerbate pre-existing dyskinesia. In controlled clinical trials (Studies 1, 2, 3, and 4) [see Clinical Studies (14) ] , the incidence of dyskinesia was 15% for NOURIANZ 20 mg, 17% for NOURIANZ 40 mg, and 8% for placebo, in combination with levodopa. One percent of patients treated with either NOURIANZ 20 mg or 40 mg discontinued treatment because of dyskinesia, compared to 0% for placebo. 4 CONTRAINDICATIONS None. None ( 4 ).

Related Medications

Medical Disclaimer

This drug information is for educational purposes only and should not replace professional medical advice. Drug information is sourced from the FDA National Drug Code Directory and Structured Product Labeling. Always consult with a healthcare provider before starting, stopping, or changing any medication.