Drug Interaction Report

Sapropterin and Levodopa Oral Inhalation: Interaction Details

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Sapropterin

Javygtor Kuvan Kuvan® Zelvysia
+

Levodopa Oral Inhalation

Inbrija Inbrija®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Updated Aug 8, 2026
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Interaction severity
Major
Potentially serious — often needs a change or close monitoring.
How we grade severity & evidence

Severity levels

  • Contraindicated: These should generally not be used together.
  • Major: Potentially serious — often needs a change or close monitoring.
  • Moderate: Can be significant — usually manageable with monitoring.
  • Minor: Usually limited clinical impact.

Evidence grades

  • Established: Well documented — supported by controlled studies or strong clinical data.
  • Probable: Good supporting evidence, though not definitively proven.
  • Suspected: Some evidence suggests this interaction, but it is not well established.
  • Possible: Limited or conflicting evidence; the interaction may occur.
  • Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.

Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.

Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
unspecified
Evidence
probable
Severity
Major

What happens

Increased risk of neurologic disorders

Interaction Deep Dive

Neurologic disorders such as convulsions, over-stimulation, and irritability have been reported with the concomitant use of levodopa and sapropterin in patients with underlying neurologic disorders. Monitor for changes in neurologic status when levodopa and sapropterin are used concomitantly1.

Why it happens (mechanism)

Increased tyrosine availability

Literature reports

1 report — tap to read

a) Three patients with underlying neurologic disorders had convulsions, exacerbation of convulsions, over-stimulation, or irritability with concomitant use of levodopa and sapropterin in a 10-year postmarketing surveillance program for another formulation of sapropterin used for a non-phenylketonuria indication 1.

Common questions

Can I take Sapropterin and Levodopa Oral Inhalation together?

Increased risk of neurologic disorders Always confirm with your pharmacist or prescriber before making any change.

How serious is the Sapropterin and Levodopa Oral Inhalation interaction?

It is rated major. Potentially serious — often needs a change or close monitoring.

How quickly could this interaction happen?

The documented onset is "unspecified". The timing of this interaction is not well characterized.

How strong is the evidence for this interaction?

The evidence is graded "probable". Good supporting evidence, though not definitively proven.

Questions for your pharmacist

  • Does my dose of Sapropterin or Levodopa Oral Inhalation need adjusting while I take them together?
  • What symptoms should prompt me to call you or my prescriber right away?
  • Does the timing of my doses matter for this combination?
  • Is there a safer alternative to one of these medications for me?

References (1)

  1. Product Information: KUVAN(R) oral tablets, oral powder for solution, sapropterin dihydrochloride oral tablets, oral powder for solution. BioMarin Pharmaceutical Inc (per FDA), Novato, CA, 2019. DailyMed
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