Medication use
Metformin Before Contrast Imaging or a Procedure
If you take metformin and have a procedure or contrast scan planned, tell the ordering clinician and imaging team. Whether it needs to be paused depends on details such as kidney function and the procedure. Do not decide from a generic internet schedule.
What to do next
- Provide the exact metformin product, dose, and current medication list.
- Ask whether the scan uses contrast and whether your kidney function needs review.
- If instructed to hold metformin, get the last-dose, monitoring, and restart directions in writing.
- Ask who confirms it is safe to restart and whether any laboratory testing is needed first.
When to contact your care team
Metformin has a rare but serious lactic-acidosis risk. Severe weakness, unusual sleepiness, breathing difficulty, or significant illness needs urgent medical advice. Report vomiting, dehydration, or other major changes before the procedure; do not continue with an outdated plan without checking.
Put it into practice
A useful message is: “Radiology asked about metformin. Do I need to hold it for this scan, and who will tell me when to restart?” Avoid leaving the restart step undecided. Bring the written answer to the appointment along with your medication list.
Notes for your next visit
Write these in your own notes or on a printed copy. Bring them to your follow-up.
- Procedure, contrast details, and date:
- Specific hold instructions, if any:
- Who authorizes restart and how I contact them:
Sources and further reading
General education for adults. Follow your clinician’s individual plan and the current instructions for your prescribed product. This handout is not a complete medication guide. If instructions conflict, ask your clinician or pharmacist to clarify. For a medical emergency, call 911.