Skip to main content

Main menu

  • Home
  • Content
    • Current issue
    • Past issues
    • Early releases
    • Collections
    • Sections
    • Blog
    • Infographics & illustrations
    • Podcasts
    • COVID-19 Articles
  • Authors & Reviewers
    • Overview for authors
    • Submission guidelines
    • Submit a manuscript
    • Forms
    • Editorial process
    • Editorial policies
    • Peer review process
    • Publication fees
    • Reprint requests
    • Open access
    • Patient engagement
  • Members & Subscribers
    • Benefits for CMA Members
    • CPD Credits for Members
    • Subscribe to CMAJ Print
    • Subscription Prices
    • Obituary notices
  • Alerts
    • Email alerts
    • RSS
  • JAMC
    • À propos
    • Numéro en cours
    • Archives
    • Sections
    • Abonnement
    • Alertes
    • Trousse média 2023
  • CMAJ JOURNALS
    • CMAJ Open
    • CJS
    • JAMC
    • JPN

User menu

Search

  • Advanced search
CMAJ
  • CMAJ JOURNALS
    • CMAJ Open
    • CJS
    • JAMC
    • JPN
CMAJ

Advanced Search

  • Home
  • Content
    • Current issue
    • Past issues
    • Early releases
    • Collections
    • Sections
    • Blog
    • Infographics & illustrations
    • Podcasts
    • COVID-19 Articles
  • Authors & Reviewers
    • Overview for authors
    • Submission guidelines
    • Submit a manuscript
    • Forms
    • Editorial process
    • Editorial policies
    • Peer review process
    • Publication fees
    • Reprint requests
    • Open access
    • Patient engagement
  • Members & Subscribers
    • Benefits for CMA Members
    • CPD Credits for Members
    • Subscribe to CMAJ Print
    • Subscription Prices
    • Obituary notices
  • Alerts
    • Email alerts
    • RSS
  • JAMC
    • À propos
    • Numéro en cours
    • Archives
    • Sections
    • Abonnement
    • Alertes
    • Trousse média 2023
  • Visit CMAJ on Facebook
  • Follow CMAJ on Twitter
  • Follow CMAJ on Pinterest
  • Follow CMAJ on Youtube
  • Follow CMAJ on Instagram
Practice

Metformin and intravenous contrast

Mark Otto Baerlocher, Murray Asch and Andy Myers
CMAJ January 08, 2013 185 (1) E78; DOI: https://doi.org/10.1503/cmaj.090550
Mark Otto Baerlocher
From the Department of Radiology (Baerlocher), Royal Victoria Hospital, Barrie, Ont.; and the Department of Radiology (Asch, Myers), Lakeridge Health Corporation, Oshawa, Ont.
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • For correspondence: mark.baerlocher@alumni.utoronto.ca
Murray Asch
From the Department of Radiology (Baerlocher), Royal Victoria Hospital, Barrie, Ont.; and the Department of Radiology (Asch, Myers), Lakeridge Health Corporation, Oshawa, Ont.
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Andy Myers
From the Department of Radiology (Baerlocher), Royal Victoria Hospital, Barrie, Ont.; and the Department of Radiology (Asch, Myers), Lakeridge Health Corporation, Oshawa, Ont.
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site

Metformin is excreted by the kidneys

Metformin is used in type 2 diabetes mellitus to decrease the amount of glucose produced by the liver and to increase the body’s response to insulin. In patients with renal failure (acute or chronic), the renal clearance of metformin is decreased, and there is an associated risk of lactic acidosis, which has a mortality rate of up to 50%.1 Some patients who receive intravenous contrast may experience a deterioration of renal function (contrast-induced nephropathy). Although the points in this article discuss the use of intravenous contrast, the same principles apply to intra-arterial contrast.

Use of metformin is not a contraindication to intravenous contrast administration

Metformin in isolation is not considered a risk factor for contrast-induced nephropathy,2 but particular attention must be paid to patients taking metformin who are scheduled to undergo contrast-enhanced examination (e.g., enhanced computed tomography [CT], angiography, venography).3 Many physicians are particularly cautious in the case of elderly patients aged greater than 80 years.

For most patients, metformin should be stopped at the time of contrast administration

There is some controversy about when to stop and restart metformin for patients scheduled to undergo intravenous contrast-enhanced examinations.4 The guidelines from the Canadian Association of Radiologists2 state that patients taking metformin who have an estimated glomerular filtration rate (eGFR) of less than 60 mL/min should stop taking metformin at the time of contrast administration. The European Society of Urogenital Radiology advocates stopping metformin 48 hours before CT for patients with an eGFR of less than 45 mL/min.5

Restarting metformin depends on renal function and the volume of contrast used

Guidelines from the Canadian Association of Radiologists2 state that patients taking metformin who have an eGFR of less than 60 mL/min should restart the drug no sooner than 48 hours after contrast administration and only if renal function remains stable (< 25% increase in creatinine above baseline). Patients with an eGFR above 60 mL/min who receive a larger amount of intravenous contrast (> 100 mL; e.g., CT of the abdomen or pelvis, CT angiography of the aorta or lower extremities) should restart metformin no earlier than 48 hours after the procedure.3

For small volumes of contrast, patients with normal renal function taking metformin may not require any changes in care

If patients with normal renal function who are taking metformin receive less than 100 mL of intravenous contrast (e.g., enhanced CT of the brain), stopping metformin and/or rechecking creatinine levels 48 hours after the procedure may be unnecessary, because the risk of contrast-induced nephropathy in patients with normal renal function is very low.5

Footnotes

  • Competing interests: None declared.

  • This article has been peer reviewed.

References

    1. Misbin RI,
    2. Green L,
    3. Stadel BV,
    4. et al
    . Lactic acidosis in patients with diabetes treated with metformin. N Engl J Med 1998;338:265–6.
    1. Benko A,
    2. Fraser-Hill M,
    3. Magner P,
    4. et al.
    Canadian Association of Radiologists. Canadian Association of Radiologists: consensus guidelines for the prevention of contrast-induced nephropathy. Can Assoc Radiol J 2007;58:79–87.
    1. Thomsen HS,
    2. Morcos SK
    . Contrast media and metformin. Guidelines to diminish the risk of lactic acidosis in non-insulin dependent diabetics after administration of contrast media. Eur Radiol 1999;9:738–40.
    1. Goergen SK,
    2. Rumbold G,
    3. Compton G,
    4. et al
    . Systematic review of current guidelines, and their evidence base, on risk of lactic acidosis after administration of contrast medium for patients receiving metformin. Radiology 2010; 254:261–9.
    1. Stacul F,
    2. van der Molen AJ,
    3. Reimer P,
    4. et al.
    Contrast Media Safety Committee of European Society of Urogenital Radiology (ESUR). Contrast induced nephropathy: updated ESUR Contrast Media Safety Committee guidelines [review]. Eur Radiol 2011;21:2527–41.

Content

  • Current issue
  • Past issues
  • Collections
  • Sections
  • Blog
  • Podcasts
  • Alerts
  • RSS
  • Early releases

Information for

  • Advertisers
  • Authors
  • Reviewers
  • CMA Members
  • CPD credits
  • Media
  • Reprint requests
  • Subscribers

About

  • General Information
  • Journal staff
  • Editorial Board
  • Advisory Panels
  • Governance Council
  • Journal Oversight
  • Careers
  • Contact
  • Copyright and Permissions
  • Accessibiity
  • CMA Civility Standards
CMAJ Group

Copyright 2023, CMA Impact Inc. or its licensors. All rights reserved. ISSN 1488-2329 (e) 0820-3946 (p)

All editorial matter in CMAJ represents the opinions of the authors and not necessarily those of the Canadian Medical Association or its subsidiaries.

To receive any of these resources in an accessible format, please contact us at CMAJ Group, 500-1410 Blair Towers Place, Ottawa ON, K1J 9B9; p: 1-888-855-2555; e: cmajgroup@cmaj.ca

Powered by HighWire