Colesevelam and Glipizide: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Glipizide
Colesevelam
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 glipiZIDE exposure
Interaction Deep Dive
Colesevelam may decrease the bioavailability of glipiZIDE by reducing its gastrointestinal absorption. In a manufacturer study, concurrent administration with colesevelam reduced the drug exposure of glipiZIDE; however, AUC and Cmax changes were minimal when glipiZIDE was given 4 hours prior to colesevelam. In patients requiring coadministration of these agents, glipiZIDE should be taken at least 4 hours prior to colesevelam1.
Why it happens (mechanism)
Reduced gastrointestinal absorption of glipiZIDE by binding with colesevelam
Literature reports
1 report — tap to read
a) Coadministration of glipiZIDE 20 mg and colesevelam 3.75 g resulted in a 12% and 13% mean reduction in glipiZIDE AUC and Cmax, respectively. When glipiZIDE was given 4 hours prior to colesevelam, the mean change in glipiZIDE AUC was -4% and there was no change in Cmax 1.
Common questions
Can I take Colesevelam and Glipizide together?
Decreased glipiZIDE exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Colesevelam and Glipizide interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
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 Colesevelam 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 (1)
- Product Information: WELCHOL oral tablets, oral suspension, colesevelam HCl oral tablets, oral suspension. Daiichi Sankyo, Inc. (per FDA), Parsippany, NJ, 2012. DailyMed
Keep reading about Glipizide
Keep reading about Colesevelam
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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