Drug interactions
Cefalexin + Metformin
Severity: Moderate
Cefalexin and Metformin: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Cefalexin inhibits renal tubular transporters of metformin, namely MATE1 and MATE2-K, which can raise metformin exposure. Higher levels matter mainly in renal impairment or other risk factors for lactic acidosis.
What this interaction means in plain words
Cefalexin and Metformin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Cefalexin belongs to Anti Bacterial; Metformin belongs to Endocrine.
Why it happens
Inhibition of renal tubular secretion of metformin via MATE transporters, reducing its clearance.
What to do
Monitor glycemic control and renal function during co-therapy, and reduce the metformin dose if renal function is impaired. Watch for signs of lactic acidosis.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Cefalexin and Metformin, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Cefalexin
- Amikacin + Cefalexin Moderate
- Avelumab + Cefalexin Moderate
- Balstilimab + Cefalexin Moderate
- Bcg vaccine live + Cefalexin Moderate
- Cefalexin + Cholera vaccine Moderate
- Cefalexin + Kanamycin Moderate
Other interactions of Metformin
Frequently asked questions
Can I take Cefalexin with Metformin?
MediHelp rates the interaction as moderate. Cefalexin and Metformin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Cefalexin inhibits renal tubular transporters of metformin, namely MATE1 and MATE2-K, which can raise metformin exposure. Higher levels matter mainly in renal impairment or other risk factors for lactic acidosis.
How serious is the interaction between Cefalexin and Metformin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor glycemic control and renal function during co-therapy, and reduce the metformin dose if renal function is impaired. Watch for signs of lactic acidosis.
What other medicines interact with Cefalexin?
MediHelp also lists interactions of Cefalexin with, for example, Amikacin, Avelumab, Balstilimab. The full list is on the Cefalexin page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
