Drug interactions
Metformin + Ondansetron
Severity: Minor
Metformin and Ondansetron: minor 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
Ondansetron may inhibit renal organic cation transporters and MATE proteins, which could raise metformin concentrations. Higher exposure could increase gastrointestinal effects and, rarely, lactic acidosis in patients with renal impairment.
What this interaction means in plain words
Metformin and Ondansetron have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Metformin belongs to Endocrine; Ondansetron belongs to Gastrointestinal Tract.
Why it happens
Possible inhibition of OCT2/MATE-mediated renal tubular secretion of metformin by ondansetron.
What to do
No routine adjustment is needed; monitor glycemic control and renal function, particularly in patients with reduced eGFR.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Ondansetron
- Apomorphine + Ondansetron Contraindicated
- Ondansetron + Thioridazine Contraindicated
- Ondansetron + Vandetanib Contraindicated
- Adagrasib + Ondansetron Major
- Amiodarone + Ondansetron Major
- Amisulpride + Ondansetron Major
Other interactions of Metformin
Frequently asked questions
Can I take Metformin with Ondansetron?
MediHelp rates the interaction as minor. Metformin and Ondansetron have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Ondansetron may inhibit renal organic cation transporters and MATE proteins, which could raise metformin concentrations. Higher exposure could increase gastrointestinal effects and, rarely, lactic acidosis in patients with renal impairment.
How serious is the interaction between Metformin and Ondansetron?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine adjustment is needed; monitor glycemic control and renal function, particularly in patients with reduced eGFR.
What other medicines interact with Ondansetron?
MediHelp also lists interactions of Ondansetron with, for example, Apomorphine, Thioridazine, Vandetanib. The full list is on the Ondansetron page.
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