Istradefylline

Aric tablet is an adenosine receptor antagonist indicated as adjunctive treatment to levodopa/carbidopa in adult patients with Parkinson's disease experiencing "off" episodes.

Dosage & Administration

The recommended dosage of Istradefylline 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. Patients who smoke 20 or more cigarettes per day (or the equivalent of another tobacco product) the recommended dosage is 40 mg once daily.
Patients with Hepatic Impairment
: Maximum recommended dosage with moderate hepatic impairment is 20 mg once daily, use of Istradefylline in patients with severe hepatic impairment should be avoided.
Use in Children
: Safety and effectiveness of Istradefylline in pediatric patients have not been established.

The most common adverse reactions of Aric are dyskinesia, dizziness, constipation, nausea, hallucination, and insomnia.

Istradefylline is a selective adenosine A
2A
receptor inhibitor. These receptors are found in the basal ganglia, a region of the brain that suffers degeneration in Parkinson's disease, and is also significantly involved in motor control. A
2A
receptors are also expressed on GABAergic medium spiny neurons within the indirect striato-pallidal pathway. The GABAergic action of this pathway is thereby reduced. Istradefylline has 56 times the affinity for A
2A
receptors than A
1
receptors.