Metformin and Levoketoconazole: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Metformin
Levoketoconazole
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
Increased metFORMIN exposure and an increased risk of metFORMIN-related adverse effects
Interaction Deep Dive
Concomitant use of levoketoconazole (an OCT-2 and MATE inhibitor) and metFORMIN (an OCT-2 and MATE substrate) may increase the plasma concentration of metFORMIN and may increase the risk of metFORMIN-related adverse effects. Coadministration of levoketoconazole 450 mg twice daily with metFORMIN increased metFORMIN AUC and Cmax by 220% and 182%, respectively, compared with administration of metFORMIN alone. If concomitant use is necessary, monitor blood glucose, kidney function, and vitamin B12 and adjust metFORMIN dosage as needed during levoketoconazole titration1.
Why it happens (mechanism)
Inhibition of OCT-2 and MATE transport of metFORMIN by levoketoconazole
Literature reports
1 report — tap to read
a) Coadministration of levoketoconazole 450 mg twice daily with metFORMIN increased metFORMIN AUC and Cmax by 220% and 182%, respectively, compared with administration of metFORMIN alone (N=17) 1.
Common questions
Can I take Metformin and Levoketoconazole together?
Increased metFORMIN exposure and an increased risk of metFORMIN-related adverse effects Always confirm with your pharmacist or prescriber before making any change.
How serious is the Metformin and Levoketoconazole 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.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Metformin or Levoketoconazole 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: RECORLEV(R) oral tablets, levoketoconazole oral tablets. Xeris Pharmaceuticals Inc (per FDA), Chicago, IL, 2023. DailyMed
Keep reading about Metformin
Keep reading about Levoketoconazole
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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