Medicare AdvantagePrior AuthMedium impact
Nourianz™ (istradefylline) (Revised)
Humana·Neurology, Pharmacy, Geriatrics·Medicare Advantage
Effective date
Jan 1, 2022
We identified it
Jun 25, 2026
Summary
Humana updated its Nourianz (istradefylline) prior authorization policy for Medicare Advantage members with Parkinson's disease. The policy requires prior authorization confirming the member has documented "off" periods on carbidopa/levodopa and has failed or has contraindications to at least two adjunctive medication classes (dopamine agonists, MAO-B inhibitors, or COMT inhibitors) before Nourianz can be covered. This is a routine policy revision effective January 1, 2022, with the most recent update dated November 26, 2025.
Action Required
By December 15, 2025: Billing and prior authorization teams must ensure Nourianz (istradefylline) claims for Medicare Advantage members include documentation of: (1) Parkinson's disease diagnosis, (2) documented "off" periods on carbidopa/levodopa therapy, (3) current concurrent use of carbidopa/levodopa, and (4) evidence of treatment failure with or contraindication/intolerance to at least TWO of the following—dopamine agonists (pramipexole IR, ropinirole IR), MAO-B inhibitors (rasagiline, selegiline), or COMT inhibitors (entacapone). Update prior authorization templates and provider education materials to reflect these five required criteria. Train clinical reviewers to verify all criteria are met before approval. Claims submitted without complete documentation of the required prior treatment failures will be denied.