Drug Interaction Report

Naloxegol and Darunavir: Interaction Details

A pharmacist-reviewed analysis of the Naloxegol and Darunavir interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

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

Darunavir

No brand names on record
+

Naloxegol

Movantik Movantik®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
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Interaction severity
Contraindicated
These should generally not be used together.
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 105 documented Naloxegol interactions, 27 are rated contraindicated — including this one.
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
Contraindicated

What happens

Increased naloxegol exposure

Interaction Deep Dive

Coadministration of darunavir/ritonavir and naloxegol is contraindicated due to potential for precipitating opioid withdrawal symptoms. Darunavir/ritonavir is an inhibitor of CYP3A; naloxegol is a CYP3A substrate. Coadministration of once daily oral ketoconazole 400 mg (a strong CYP3A4 inhibitor) and naloxegol 25 mg increased the naloxegol Cmax by 9.58-fold and the AUC by 12.85-fold. Additionally, coadministration of oral diltiazem 240 mg extended-release (a moderate CYP3A4 inhibitor) with naloxegol 25 mg increased the naloxegol Cmax by 2.86-fold and the AUC by 3.41-fold2.

Why it happens (mechanism)

Inhibition of CYP3A4-mediated metabolism of naloxegol

Literature reports

1 report — tap to read

a) Coadministration of once daily oral ketoconazole 400 mg (a strong CYP3A4 inhibitor) and naloxegol 25 mg increased the naloxegol Cmax by 9.58-fold and the AUC by 12.85-fold. Additionally, coadministration of oral diltiazem 240 mg extended-release (a moderate CYP3A4 inhibitor) with naloxegol 25 mg increased the naloxegol Cmax by 2.86-fold and the AUC by 3.41-fold 1.

Common questions

Can I take Naloxegol and Darunavir together?

Increased naloxegol exposure Always confirm with your pharmacist or prescriber before making any change.

How serious is the Naloxegol and Darunavir interaction?

It is rated contraindicated. These should generally not be used together.

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 Naloxegol or Darunavir 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 (2)

  1. Product Information: MOVANTIK(TM) oral tablets, naloxegol oral tablets. AstraZeneca (per manufacturer), Wilmington, DE, 2014. DailyMed
  2. Product Information: PREZISTA(R) oral suspension, oral tablets, darunavir oral suspension, oral tablets. Janssen Therapeutics (per FDA), Titusville, NJ, 2022. DailyMed
Was this write-up helpful?
Darunavir

Keep reading about Darunavir

All Darunavir interactions (115)
Also serious with: Lovastatin Ivabradine Colchicine Lurasidone
Naloxegol

Keep reading about Naloxegol

All Naloxegol interactions (105) Naloxegol drug information
Also serious with: Ceritinib Boceprevir Clarithromycin Voriconazole
Beyond drug–drug

These medications also interact with supplements

Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:

Darunavir + Activated Charcoal Grapefruit St. John's Wort Acacia Rigidula Adrafinil African Wild Potato American Elder Astaxanthin + 137 more
Naloxegol + Activated Charcoal Grapefruit St. John's Wort Acacia Rigidula Adrafinil African Wild Potato American Elder Astaxanthin + 130 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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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.