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.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action The precise mechanism by which istradefylline exerts its therapeutic effect in Parkinson’s disease is unknown. In in vitro studies and in in vivo animal studies, istradefylline was demonstrated to be an adenosine A 2A receptor antagonist. 12.2 Pharmacodynamics Cardiac Electrophysiology The effect of NOURIANZ (40 mg or 160 mg [4 times the maximum recommended dosage] once daily for 14 days) on the QTc interval was evaluated in a randomized, placebo and moxifloxacin-controlled, multiple-dose, blinded, parallel group study. There was no clinically significant prolongation of QTc interval or relationship between changes in QTc and concentrations of istradefylline. 12.
Indications
- 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 ).
Common Doses
- 20 mg
- 40 mg
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.
Contraindications
- 4 CONTRAINDICATIONS None. None ( 4 ).
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.
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.