Drug Interaction Report

Famotidine and Dasatinib: Interaction Details

A pharmacist-reviewed analysis of the Famotidine and Dasatinib 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

Dasatinib

Phyrago Sprycel Sprycel®
+

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 217 documented Famotidine interactions, 189 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
probable
Severity
Major

What happens

Reduced dasatinib exposure and an increased risk of QT interval prolongation

Interaction Deep Dive

Avoid coadministration of dasatinib and famotidine as this may result in decreased dasatinib exposure. Coadministration of dasatinib and famotidine resulted in 61% and 63% decrease in mean dasatinib AUC and Cmax, respectively. Consider the use of antacids in place of famotidine. Concomitant use may also increase the risk of QT prolongation. Correct hypomagnesemia or hypokalemia before and during dasatinib therapy1.

Why it happens (mechanism)

Inhibition of gastric acid; additive QT interval prolongation

Literature reports

2 reports — tap to read

a) Following a dose of famotidine, the administration of dasatinib 10 hours later resulted in a 61% and 63% reduction in mean dasatinib AUC and Cmax, respectively 1.

b) No clinically significant differences in the pharmacokinetics of dasatinib were observed following concomitant use with famotidine (H2 receptor antagonist) 2.

Common questions

Can I take Famotidine and Dasatinib together?

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

How serious is the Famotidine and Dasatinib 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.

From our Q&A

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

Questions for your pharmacist

  • Does my dose of Famotidine or Dasatinib 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: SPRYCEL(R) oral tablets, dasatinib oral tablets. Bristol-Myers Squibb Company (per FDA), Princeton, NJ, 2023. DailyMed
  2. Product Information: PHYRAGO oral tablets, dasatinib oral tablets. Nanocopoeia, LLC (per FDA), New Brighton, MN, 2023. DailyMed
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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:

Dasatinib + Activated Charcoal American Hellebore Arsenic Cesium Ephedra Grapefruit Sida Cordifolia St. John's Wort + 138 more
Famotidine + Activated Charcoal African Wild Potato Banderol Beer Biofeedback Caffeic Acid Coffee Charcoal Dendrobium + 33 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.