Cimetidine and Octreotide: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Cimetidine
Octreotide
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
Decreased octreotide bioavailability
Interaction Deep Dive
Concomitant administration of octreotide and drugs that alter the pH of the upper GI tract (eg, proton pump inhibitors [PPIs], H2-receptor antagonists, and antacids) may alter the absorption of octreotide and lead to a reduction in bioavailability. In a study, coadministration of esomeprazole 40 mg orally on days 2 through 7 and octreotide 20 mg orally on day 1 and 7 significantly decreased octreotide AUC by 41% and Cmax by 45%. Coadministration may require increased doses of octreotide1.
Why it happens (mechanism)
Reduced absorption of octreotide
Literature reports
1 report — tap to read
a) Coadministration of esomeprazole 40 mg orally on days 2 through 7 and octreotide 20 mg orally on day 1 and 7 significantly decreased octreotide AUC by 41% (mean ratio, 0.59; 90% CI, 0.4 to 0.88) and Cmax by 45% (mean ratio, 0.55; 90% CI, 0.4 to 0.75) 1.
Common questions
Can I take Cimetidine and Octreotide together?
Decreased octreotide bioavailability Always confirm with your pharmacist or prescriber before making any change.
How serious is the Cimetidine and Octreotide 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 "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Cimetidine or Octreotide 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)
- Product Information: MYCAPSSA(R) oral delayed-release capsules, octreotide oral delayed-release capsules. Chiasma Inc (per manufacturer), Cincinnati, OH, 2020. DailyMed
Keep reading about Cimetidine
Keep reading about Octreotide
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.
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