Cimetidine and Glipizide: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Cimetidine
Glipizide
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
Hypoglycemia
Interaction Deep Dive
The concurrent use of cimetidine 900 to 1200 mg daily has been reported to increase the concentration of glipiZIDE by 25%, glyburide by 30%, tolbutamide by 20%, and the levels of gliclazide. Both cimetidine and ranitidine have been reported to increase the glipiZIDE AUC by about 20% to 25%, while augmenting glipiZIDE hypoglycemic effect12.
Why it happens (mechanism)
Inhibition of glipiZIDE metabolism by cimetidine
Common questions
Can I take Cimetidine and Glipizide together?
Hypoglycemia Always confirm with your pharmacist or prescriber before making any change.
How serious is the Cimetidine and Glipizide interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
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 Cimetidine or Glipizide 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 anything you'd monitor while I'm on both?
References (2)
- MacWalter RS, Debani EI, Feeley J, et al: Potentiation by ranitidine of the hypoglycaemic response to glipizide in diabetic patients. Br J Clin Pharmacol 1985; 19:121P-122P.
- Feely J & Peden N: Enhanced sulphonylurea-induced hypoglycaemia with cimetidine. Br J Clin Pharmacol 1983; 15:607P.
Keep reading about Cimetidine
Keep reading about Glipizide
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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