Istradefylline

NOURIANZ

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Pronunciation: is-tra-DEF-i-lin (NYOO-ree-anz)

Istradefylline ballicule: receptor binding, kinetics and half-life diagram — Mechanism of action: Istradefylline ballicule

Istradefylline NOURIANZ mascot mnemonic cartoon — Visual mnemonic: Istradefylline mascot
**“Nori is tradin’ felines”**
tremor/spilling coffee → Parkinson’s medication
coffee → similar structure to caffeine, but not a methylxanthine
Manuel Noriega

What it isAdenosine A2A receptor antagonist; off episodes in Parkinson disease.

Why this oneIt reduces off time without directly stimulating dopamine receptors, offering a mechanistically distinct levodopa add-on.

What limits itDyskinesia can worsen; hallucinations and impulse-control disorders occur, and CYP3A4 modifiers alter exposure.

Istradefylline molecular structure (skeletal formula) — Molecular structure: Istradefylline

FDA-approved for

Parkinson OFF episodes (2019)

FDA label

Read the full label on DailyMed ↗

FDA dosing	Population	Start	Target	Max
Adjunct to levodopa/carbidopa for Parkinson's 'off' episodes	Adult	20 mg QD	20 mg QD	40 mg QD
Same, in patients smoking ≥20 cigarettes/day	Adult (heavy smoker)	40 mg QD	40 mg QD	40 mg QD

Renal No adjustment needed

Hepatic Moderate impairment (Child-Pugh B): max 20 mg QD; avoid in severe impairment.

Instructions

May be taken with or without food
Initial dose titration is not required

Available strengths

tab 20, 40 mg

Cautions

May cause or worsen dyskinesia
Hallucinations/psychotic behavior — avoid in major psychotic disorder
Impulse control/compulsive behaviors

Adverse reactions

Dyskinesia
Dizziness
Constipation
Nausea
Hallucination
Insomnia

Pregnancy May cause fetal harm (animal teratogenicity at clinically relevant exposures); no adequate human data.

Lactation No human data; present in rat milk.

Cost

Istradefylline (NOURIANZ)

Strength		#/mo	generic $/mo	CostPlus
20 mg	tab	30 qd		not offered
40 mg	tab	30 qd		not offered

NADAC is a voluntary CMS survey of what retail community pharmacies pay for the drugs they stock. Istradefylline is dispensed outside retail pharmacies, so it rarely appears on surveyed invoices.

Generic entry2027 est.

NO BOXED WARNINGS

Principal riskWorsening dyskinesia; hallucinations

Classes and tags

Clinical profile

Therapeutic safety burden2 / 4

Overdose danger2 / 4

Weight-gain liability0 / 4

Sedation liability1 / 4

QT / Torsades0 / 4

Direct muscarinic antagonism0 / 4

Embryofetal risk1 / 4

Legacy pregnancy categoryNot assigned — PLLR-era drug

Defining liabilityOrthostasis, hallucinations, dyskinesia and impulse-control symptoms; abrupt withdrawal can be hazardous.

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Memory aids: interaction avatars

CYP1A2 substrate

CYP3A4 substrate

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