Lansoprazole and Atezolizumab: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Lansoprazole
Atezolizumab
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
Impaired efficacy of atezolizumab
Interaction Deep Dive
Proton pump inhibitors (PPIs) administered prior to and during atezolizumab therapy may decrease the effectiveness of atezolizumab. In a post-hoc analysis of pooled data from 5 pivotal trials in patients with NSCLC, the use of a PPI was associated with a significant decrease in the magnitude of the OS and PFS benefit of atezolizumab compared with PPI non-use. Evaluate the clinical need for use of a PPI and consider discontinuation prior to initiation of atezolizumab if possible1.
Why it happens (mechanism)
Decrease in gut bacteria diversity by proton pump inhibitors
Literature reports
1 report — tap to read
a) In a post-hoc analysis of pooled data from 5 pivotal trials (IMpower130, IMpower131, IMpower150, OAK, and POPLAR) in patients with NSCLC (N=4458), the use of a PPI (any use documented as continuing during treatment; n=1225; omeprazole, n=559; pantoprazole, n=391; esomeprazole, n=136; lansoprazole, n=104; rabeprazole, n=27; dexlansoprazole, n=5; vanoprazan, n=3) was associated with a significant decrease in the magnitude of atezolizumab overall survival (OS) benefit (as assessed by HR of atezolizumab vs comparator arms) compared with PPI non-use (HR 1; 95% CI, 0.85 to 1.17 vs HR, 0.76; 95% CI, 0.69 to 0.83). The use of a PPI also demonstrated a significant decrease in the magnitude of progression-free survival (PFS) benefit with atezolizumab (HR 0.93; 95% CI, 0.76 to 1.13 vs HR, 0.75; 95% CI, 0.65 to 0.88). Consistent findings were observed across trials; indicating a decrease in atezolizumab OS benefit when being used as both first-line chemoimmunotherapy and later line monotherapy. In patients randomized to atezolizumab (n=2723), PPI use was associated with significantly worse OS (adjusted HR, 1.23; 95% CI, 1.09 to 1.37) and PFS (adjusted HR, 1.15; 95% CI, 1.03 to 1.28) compared with PPI non-use. In the comparator arms randomized to therapy without atezolizumab (n=1735), no significant association between PPI use and altered OS or PFS was observed 1.
Common questions
Can I take Lansoprazole and Atezolizumab together?
Impaired efficacy of atezolizumab Always confirm with your pharmacist or prescriber before making any change.
How serious is the Lansoprazole and Atezolizumab 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 Lansoprazole or Atezolizumab 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 (1)
- Hopkins AM, Badaoui S, Kichenadasse G, et al: Efficacy of atezolizumab in patients with advanced NSCLC receiving concomitant antibiotic or proton pump inhibitor treatment: pooled analysis of five randomized control trials. J Thorac Oncol 2022; 17(6):758-767. PubMed
Keep reading about Lansoprazole
Keep reading about Atezolizumab
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:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist