Esomeprazole and Palbociclib: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Palbociclib
Esomeprazole
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.
What happens
Reduced efficacy of palbociclib
Interaction Deep Dive
Coadministration of palbociclib with proton pump inhibitors (PPIs) may56 or may not 72 decrease progression-free survival and overall survival in patients receiving breast cancer treatment. Consider the use of a H2-antagonist instead of a PPI in this population. If coadministration is required, use a PPI cautiously, especially long term 1, and consider palbociclib in tablet formulation 2.
Why it happens (mechanism)
Unknown
Literature reports
4 reports — tap to read
a) In a retrospective study of patients with estrogen-positive, HER2-negative metastatic breast cancer (N=112), concomitant administration of palbociclib with a proton pump inhibitor (PPI) significantly shortened progression-free survival (PFS) time compared with patients taking palbociclib alone with endocrine therapy (14 vs 37.9 months). Palbociclib was administered orally once daily at lunchtime for 21 days, followed by 7 days off, with either fulvestrant or letrozole. Most patients received palbociclib 125 mg (61.6%), though dose reductions for toxicity were made to 100 mg (26.8%) and 75 mg (9.8%) if necessary. Patients on concomitant PPI therapy received either lansoprazole 15 mg (n=42), omeprazole 10 mg (n=11), esomeprazole 20 mg (n=1), or pantoprazole 20 mg (n=2) once daily in the morning with breakfast. The possible mechanism for this interaction may be that the increase in gastric pH may have lowered palbociclib plasma concentrations, therefore affecting treatment efficacy. Caution should be used especially during long term use of PPIs in this population 1.
b) In drug interaction trials in healthy subjects, coadministration of a single palbociclib 125 mg tablet with multiple doses of rabeprazole under overnight fasted conditions had no effect on the pharmacokinetics of palbociclib when compared with palbociclib tablet administered alone 3. Under fasted conditions, coadministration of a single palbociclib 125 mg capsule with multiple doses of rabeprazole decreased palbociclib AUC(inf) and Cmax by 62% and 80%, respectively, when compared to palbociclib capsule alone; in fed conditions, AUC(inf) and Cmax were decreased by 41% and 13% 4.
c) Concomitant use of palbociclib and proton pump inhibitors (PPIs) resulted in a significantly shorter median progression-free survival compared with non-users in 2 retrospective studies of patients with breast cancer (10.6 months vs not reached; dosage form not specified 5; 25.3 months vs 39.8 months; capsule formulation); overall survival (OS) was also significantly shorter in concomitant users compared with non-users in 1 of the studies (1-year OS, 83.1% vs 94%; 2-year OS, 69.5% vs 89.3%; capsule formulation) 6. Patients received endocrine therapy (fulvestrant or aromatase inhibitor) and PPI therapy consisted of dexlansoprazole, esomeprazole, ilaprazole, lansoprazole, omeprazole, pantoprazole, or rabeprazole 56.
d) Concomitant use of palbociclib and proton pump inhibitors (PPIs) did not significantly impact median progression-free survival compared with non-users in 2 retrospective studies of patients with metastatic breast cancer (14.4 months vs 15.8 months; capsule formulation 7; 20.6 months vs 21 months; tablet formulation 2). Patients received endocrine therapy (fulvestrant or aromatase inhibitor) and PPIs included lansoprazole, pantoprazole, esomeprazole, rabeprazole, and omeprazole 72.
Common questions
Can I take Esomeprazole and Palbociclib together?
Reduced efficacy of palbociclib Always confirm with your pharmacist or prescriber before making any change.
How serious is the Esomeprazole and Palbociclib 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 Esomeprazole or Palbociclib 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 (7)
- Del Re M, Omarini C, Diodati L, et al: Drug-drug interactions between palbociclib and proton pump inhibitors may significantly affect clinical outcome of metastatic breast cancer patients. ESMO Open 2021; 6(5):100231. PubMed
- Schieber T, Steele S, Collins S, et al: Effect of concurrent proton pump inhibitors with palbociclib tablets for metastatic breast cancer. Clin Breast Cancer 2023; 23(6):658-663. PubMed
- Product Information: IBRANCE(R) oral tablets, palbociclib oral tablets. Pfizer Labs (per FDA), New York, NY, 2022. DailyMed
- Product Information: IBRANCE(R) oral capsules, palbociclib oral capsules. Pfizer Labs (per FDA), New York, NY, 2022. DailyMed
- Caglayan D, Kocak MZ, Geredeli C, et al: The effect of concomitant use of proton pump inhibitors with CDK 4/6 inhibitors on survival in metastatic breast cancer. Eur J Clin Pharmacol 2023; 79(2):243-248.
- Lee JE, Kwon SH, Kwon S, et al: Concomitant use of proton pump inhibitors and palbociclib among patients with breast cancer. JAMA Netw Open 2023; 6(7):e2324852. PubMed
- Odabas H, Dogan A, Ozcelik M, et al: Does proton pump inhibitors decrease the efficacy of palbociclib and ribociclib in patients with metastatic breast cancer. Medicina (Kaunas) 2023; 59(3):557-. DOI
Keep reading about Palbociclib
Keep reading about Esomeprazole
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