False result warning for INRatio coagulation monitoring system

GPs should not use the Alere INRatio coagulation monitoring system in patients with anaemia or raised fibrinogen levels, the manufacturer has advised, as there is a risk that the INR will be underestimated.

It is recommended that patients using the Alere INRatio system have their INR periodically verified using a laboratory method. | SCIENCE PHOTO LIBRARY
It is recommended that patients using the Alere INRatio system have their INR periodically verified using a laboratory method. | SCIENCE PHOTO LIBRARY

Patients with the following conditions should be switched to a laboratory INR method for monitoring their anticoagulant therapy:

  • anaemia of any type with hematocrit <30% (Alere INRatio PT/INR Test Strips) or <25% (Alere INRatio2 PT/INR Test Strips, Heparin Insensitive)
  • any conditions associated with elevated fibrinogen levels, including:
    • acute inflammatory conditions (eg, acute viral or bacterial infections such as pneumonia or influenza)
    • chronic inflammatory conditions (eg, rheumatoid arthritis, Crohn’s disease, ulcerative colitis, infectious liver diseases or inflammatory kidney diseases)
    • severe infection (eg, sepsis)
    • chronically elevated fibrinogen
    • hospitalised or advanced cancer or end-stage renal disease patients requiring hemodialysis
    • any bleeding or unusual bruising, clinically observed or reported by the patient

Further information
Safety alert - INRatio and INRatio2 

If the INR result generated by the INRatio Monitor system falls within the therapeutic range, but there is reason to believe the INR could be significantly different (eg, symptoms such as bleeding or bruising which suggests the therapeutic INR value may be falsely low), testing by an alternative method should be performed immediately.
Want news like this straight to your inbox?
Sign up for our bulletins

Have you registered with us yet?

Register now to enjoy more articles and free email bulletins

Register
Already registered?
Sign in

MIMS Product Slides

Product overviews prepared by the MIMS team, in a handy slide format.

Click here

Slides are initiated, funded & reviewed by the companies specified.

Register or Subscribe to MIMS

GPs can get MIMS print & online and GPonline for free when they register online – take 2 minutes, and make sure you get your free MIMS access! If you're not a GP, you can subscribe to MIMS for full access.

Register or subscribe

MIMS Dermatology

Read the latest issue online exclusively on MIMS Learning.

Read MIMS Dermatology

MIMS Adviser

Especially created for prescribing influencers.

Request free copy

Mobile apps

MIMS: access the full drug database and quick-reference tables on the go

MIMS Diagnosis and Management: concise information on signs and symptoms, investigations and diseases