> ## Content Index
> Fetch the complete content index at: https://www.fdaweb.com/llms.txt
> Use this file to discover other available public pages before exploring further.

# Reconsider Metformin Labeling Changes: Petition
- URL: https://www.fdaweb.com/reconsider-metformin-labeling-changes-petition/
- Published: 2016-05-11T12:00:00.000Z
- Updated: 2026-09-14T21:01:56.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5135641

A [petition](https://www.regulations.gov/contentStreamer?documentId=FDA-2013-P-0298-0005&attachmentNumber=1&disposition=attachment&contentType=pdf&ref=fdaweb.com) from two Yale University School of Medicine professors of endocrinology and metabolism asks FDA to reconsider labeling changes relating to the Contraindications and Precautions sections of labeling for metformin. The petition asks that the Precautions section specifically recommend use of a lower dose of the drug (up to half the maximum dose, that is, up to 500 mg of metformin twice daily) and monitoring of renal function every three months in patients with severe renal impairment, as originally recommended in a citizen petition.

“We feel that the omission of the dose adjustment in renal impairment raises safety concerns,” the professors write. “We acknowledge that evidence with regards to dosing of metformin is limited. There is no clear definition of its therapeutic concentration available to date. Until more data are available, we suggest that a cautious approach of reduced dosing of metformin is likely to be the safest. This approach is congruent with dose adjustment for most other drugs excreted by the kidneys.”