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Istradefylline Dosage

Medically reviewed by Last updated on Oct 5, 2023.

Applies to the following strengths: 20 mg; 40 mg

Usual Adult Dose for Parkinson's Disease

Initial dose: 20 mg orally once a day

Maintenance dose: 20 to 40 mg orally once a day
Maximum dose: 40 mg/day

Use: As adjunctive treatment to levodopa/carbidopa in patients with Parkinson's disease experiencing OFF episodes.

Renal Dose Adjustments

CrCl 15 to 89 mL/min: No adjustment recommended
CrCl less than 15 mL/min: Data not available

Liver Dose Adjustments

Mild hepatic impairment (Child-Pugh A): No adjustment recommended
Moderate hepatic impairment (Child-Pugh B): Maximum dose: 20 mg orally once a day
Severe hepatic impairment (Child-Pugh C): Avoid use

Dose Adjustments

Concomitant Use with Strong CYP450 3A4 Inhibitors:

Concomitant Use with Strong CYP450 3A4 Inhibitors:

Tobacco Use:



Safety and efficacy have not been established in patients younger than 18 years.

Consult WARNINGS section for additional precautions.


Data not available

Other Comments

Administration advice:



Patient advice:

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.