Drug interactions
Contrast media + Metformin
Severity: Major
Contrast media and Metformin: major 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
Iodinated contrast can cause acute kidney injury, which reduces metformin elimination and raises the risk of metformin-associated lactic acidosis. The risk is greatest in patients with reduced eGFR, liver disease, heart failure or intra-arterial administration.
What this interaction means in plain words
Contrast media and Metformin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Contrast-induced nephrotoxicity decreases renal clearance of metformin, leading to accumulation.
What to do
Hold metformin at the time of or before imaging in patients with eGFR below 60 or risk factors, and restart after 48 hours once renal function is confirmed stable.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Metformin
Frequently asked questions
Can I take Contrast media with Metformin?
MediHelp rates the interaction as major. Contrast media and Metformin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Iodinated contrast can cause acute kidney injury, which reduces metformin elimination and raises the risk of metformin-associated lactic acidosis. The risk is greatest in patients with reduced eGFR, liver disease, heart failure or intra-arterial administration.
How serious is the interaction between Contrast media and Metformin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Hold metformin at the time of or before imaging in patients with eGFR below 60 or risk factors, and restart after 48 hours once renal function is confirmed stable.
What other medicines interact with Metformin?
MediHelp also lists interactions of Metformin with, for example, Diatrizoate meglumine / diatrizoate, Diatrizoate, Ethanol. The full list is on the Metformin page.
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