Drug Interaction Report

Indinavir and Levodopa Oral Inhalation: Interaction Details

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

Indinavir

No brand names on record
+

Levodopa Oral Inhalation

Inbrija Inbrija®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Updated Aug 8, 2026
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Interaction severity
Moderate
Can be significant — usually manageable with 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.

Of 123 documented Indinavir interactions, 24 are rated moderate — including this one.
Onset
delayed
Evidence
probable
Severity
Moderate

What happens

Enhanced levodopa effects manifested as severe dyskinesias

Interaction Deep Dive

A patient being treated for idiopathic Parkinson's disease and AIDS experienced severe dyskinesias one month after anti-HIV triple therapy was added to his regimen of levodopa. Each antiviral agent was then reintroduced separately, and indinavir induced abnormal movements after three days of starting treatment. The cytochrome P450 system catalyzes oxidative reactions produced by monoamine oxidase (MAO) or catechol-o-methyl transferase (COMT). Inhibiting this pathway with indinavir may potentiate levodopa. Further studies are required to determine if this drug interaction could be used to reduce daily levodopa requirements1.

Why it happens (mechanism)

Inhibition of cytochrome P450 enzymes

Literature reports

1 report — tap to read

a) A 66-year-old male with idiopathic Parkinson's disease and AIDS was free of dyskinesias while being treated with levodopa 700 mg to 750 mg daily in combination with a decarboxylase inhibitor. Triple anti-HIV therapy was initiated with indinavir 2400 mg daily, zidovudine 500 mg daily, and lamivudine 300 mg daily. One month later, the patient developed severe dyskinesias occurring at peak dose periods, and the on-periods lasted the whole day without fluctuations. The dyskinesias improved within five days of stopping all antiviral drugs. Each antiviral was reintroduced as a single agent, and indinavir induced abnormal movements within three days of treatment. Indinavir was then permanently discontinued 1.

Common questions

Can I take Indinavir and Levodopa Oral Inhalation together?

Enhanced levodopa effects manifested as severe dyskinesias Always confirm with your pharmacist or prescriber before making any change.

How serious is the Indinavir and Levodopa Oral Inhalation interaction?

It is rated moderate. Can be significant — usually manageable with monitoring.

How quickly could this interaction happen?

The documented onset is "delayed". Effects tend to build up gradually over days to weeks.

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 Indinavir 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 anything you'd monitor while I'm on both?

References (1)

  1. Caparros-Lefebvre D, Lannuzel A, Tiberghien F, et al: Protease inhibitors enhance levodopa effects in Parkinson's disease (letter). Mov Disord 1999; 14:535. PubMed
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Beyond drug–drug

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.