Drug Interaction Report

Rilpivirine and Famotidine: Interaction Details

A pharmacist-reviewed analysis of the Rilpivirine and Famotidine 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

Rilpivirine

Edurant Edurant® Juluca® (as a combination product containing dolutegravir, rilpivirine)
+

Famotidine

Calmicid Fluxid® Pepcid Pepcid® Pepcid® AC Pepcid® RPD Zantac Reformulated Aug 2022
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
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.

Of 73 documented Rilpivirine interactions, 65 are rated major — 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
established
Severity
Major

What happens

Reduced rilpivirine exposure and an increased risk of QT interval prolongation

Interaction Deep Dive

Use caution, concomitant administration of rilpivirine and a histamine-2 receptor antagonist may result in decreased rilpivirine plasma concentrations (increase in gastric pH). During drug interaction studies, a significant decrease in rilpivirine AUC and Cmax was observed in patients administered famotidine 2 hours prior to rilpivirine. Therefore, concomitant use of famotidine and rilpivirine is recommended only if famotidine is administered at least 12 hours before or 4 hours following rilpivirine administration12.

Why it happens (mechanism)

Changes in gastric pH; additive QT interval prolongation

Literature reports

1 report — tap to read

a) In drug interaction studies, the concomitant administration of famotidine and rilpivirine in healthy subjects or in patients with antiretroviral treatment-naive HIV-1 did not result in significant changes in rilpivirine AUC or Cmax when administered at least 12 hours before or 4 hours following rilpivirine. However, a significant decrease in rilpivirine AUC and Cmax was observed in patients receiving famotidine 2 hours prior to rilpivirine administration. Patients received a single-dose of famotidine 40 mg taken 12 hours before, 2 hours before, or 4 hours after rilpivirine 150 mg. When famotidine was administered 12 hours before, 2 hours before, or 4 hours following rilpivirine administration the mean ratio (rilpivirine plus famotidine/rilpivirine alone) estimate for rilpivirine was 0.91 (90% confidence interval (CI), 0.78 to 1.07), 0.24 (90% CI, 0.2 to 0.28), and 1.13 (90% CI, 1.01 to 1.27), respectively, for AUC. Similarly, the ratio was 0.99 (90% CI, 0.84 to 1.16), 0.15 (90% CI, 0.12 to 0.19), and 1.21 (90% CI, 1.06 to 1.39), respectively, for Cmax. The mean ratio for Cmin was not available 12.

Common questions

Can I take Rilpivirine and Famotidine together?

Reduced rilpivirine exposure and an increased risk of QT interval prolongation Always confirm with your pharmacist or prescriber before making any change.

How serious is the Rilpivirine and Famotidine 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 "established". Well documented — supported by controlled studies or strong clinical data.

From our Q&A

Real reader questions about these medications, each personally answered by our pharmacist:

Questions for your pharmacist

  • Does my dose of Rilpivirine or Famotidine 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: EDURANT(R) oral tablets, rilpivirine oral tablets. Janssen Therapeutics (per FDA), Horsham, Pa, 2024. DailyMed
  2. Product Information: EDURANT(R) PED oral tablets for suspension, rilpivirine oral tablets for suspension. Janssen Therapeutics (per FDA), Horsham, Pa, 2024. DailyMed
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Rilpivirine

Keep reading about Rilpivirine

All Rilpivirine interactions (73) Rilpivirine drug information
Also serious with: Dexlansoprazole Omeprazole Ketoconazole Topical Esomeprazole
Famotidine

Keep reading about Famotidine

All Famotidine interactions (217) Famotidine drug information
Also serious with: Dronedarone Bepridil Cisapride Levoketoconazole
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:

Rilpivirine + Activated Charcoal American Hellebore Arsenic Beer Cesium Ephedra Grapefruit Siberian Cocklebur + 167 more
Famotidine + Activated Charcoal African Wild Potato Banderol Beer Biofeedback Caffeic Acid Coffee Charcoal Dendrobium + 33 more

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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.