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# FDA Updates on Warfarin Test Meters
- URL: https://www.fdaweb.com/fda-updates-on-warfarin-test-meters/
- Published: 2018-02-12T12:00:00.000Z
- Updated: 2026-09-14T23:21:51.000Z
- Author: David McFarland
- Tags: Devices, #legacy-id-D5140738

FDA has added new information to the labeling of [warfarin international normalized ratio (INR) test meters](https://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/InVitroDiagnostics/WarfarinINRTestMeters/default.htm?utm%5Fcampaign=FDA%20adds%20information%20about%20warfarin%20INR%20test%20meters%20to%20FDA.gov&utm%5Fmedium=email&utm%5Fsource=Eloqua&elqTrackId=2A89A310F908DD005387E2D85B3A1D3A&elq=1d252ba51aa0497397085419a107a2ae&elqaid=2409&elqat=1&elqCampaignId=1711) for patients, caregivers and health care providers using the devices at home or in a clinical setting. The agency says it has received Medical Device Reporting-related adverse events about meters which may have generated inaccurate results. The devices are used to monitor patient response to warfarin, a blood thinner prescribed to prevent and treat blood clots, which must be monitored to ensure it is working effectively and being used safely.

Updates include tTips for patients and caregivers using INR test meters, such as how to take blood from a fingerstick, and how to make sure the meter is working properly, and medical conditions that could affect test results. It also includes recommendations for confirming test results.