FDA Adverse Event Injury Summary report: N

COAG-SENSE PT/INR MONITORING METER

MDR report key: 24212427 · Received January 29, 2026

Report

Report Number
MW5183057
Event Type
Injury
Date Received
January 29, 2026
Date of Event
July 7, 2025
Report Date
January 26, 2026
Manufacturer
COAGUSENSE, INC
Product Code
GJS
Adverse Event
Yes
Product Problem
Yes
Report Source
Voluntary report
Reporter Location
VA, US
Reporter Occupation
PATIENT
Health Professional
*

Narratives

Description of Event or Problem · 0

I WAS PRESCRIBED AND USED A COAG-SENSE HOME INR MONITORING SYSTEM TO MANAGE MY WARFARIN THERAPY. THE DEVICE WAS USED ACCORDING TO INSTRUCTIONS FOR HOME INR TESTING. OVER TIME, THE DEVICE PRODUCED INR READINGS THAT WERE INCONSISTENT WITH LABORATORY-CONFIRMED INR VALUES OBTAINED THROUGH VENOUS BLOOD DRAWS. THESE INACCURATE READINGS LED TO IMPROPER WARFARIN DOSING DECISIONS. THE HOME DEVICE READINGS SUGGESTED INR VALUES THAT WERE SIGNIFICANTLY DIFFERENT FROM LABORATORY RESULTS, CREATING A FALSE SENSE OF THERAPEUTIC CONTROL. AS A RESULT OF INACCURATE INR MONITORING, MY ANTICOAGULATION THERAPY WAS NOT PROPERLY MANAGED. I EXPERIENCED SERIOUS MEDICAL CONSEQUENCES CONSISTENT WITH UNDER- OR OVER-ANTICOAGULATION, INCLUDING NEUROLOGICAL INJURY AND STROKE-RELATED SYMPTOMS. THESE EVENTS REQUIRED MEDICAL EVALUATION AND ONGOING CARE. DUE TO LOSS OF CONFIDENCE IN THE ACCURACY OF THE COAG-SENSE DEVICE, I WAS FORCED TO DISCONTINUE ITS USE AND SWITCH TO ALTERNATIVE MONITORING METHODS. THE DEVICE FAILURE DIRECTLY IMPACTED MY MEDICAL TREATMENT, SAFETY, AND LONG-TERM HEALTH OUTCOMES. THE INACCURATE DEVICE READINGS WERE DISCOVERED AFTER COMPARISON WITH LABORATORY INR TESTING AND CLINICAL EVALUATION. THE HARM OCCURRED DURING NORMAL, INTENDED USE OF THE DEVICE.

Devices

Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
268560 COAG-SENSE PT/INR MONITORING METER TEST, TIME, PROTHROMBIN GJS COAGUSENSE, INC 200107

Patients

Seq Age Sex Outcome Treatment
1 45 YR Male Required Intervention| L| H| S| O CALCIUM.| METAPROLOL.| PROZAC.| VITAMIN D.| WARFARIN.