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What is an RUO/IUO?

We’ve had several posts about measuring the new oral anticoagulants, the most pressing concern for coagulation laboratories around the world as they are confronted with the need to determine the presence and levels of dabigatran, rivaroxaban, apixaban, and soon, edoxaban. Though pharmaceutical distributors reassure us there is no need for monitoring, we are confronted with patients who have renal insufficiency, who are bleeding from a possible, but undefined overdose, concerns for non-compliance, or patients with potential coagulation imbalances as are documented in cancer, liver disease, during pregnancy, obesity, small body mass, chronic DIC, or those suffering a current thrombotic episode. Especially troublesome for lab scientists are clinical efforts to screen for coagulopathies while patients are on anticoagulants, a recurring issue in which lab scientists attempt to integrate skewed results.

In vitro diagnostics (IVD) distributors are currently scrambling to meet these clinical needs, and several apparently effective assays are in development, however all are currently classified as research or investigational use only (RUO or IUO). In the past, tertiary care and reference laboratories purchased and employed RUO or IUO kits, attaching cautionary notes to the results. Knowing that third party payers may not reimburse, lab directors posted advance beneficiary notices at the time the tests were ordered or collected, warning patients and their physicians that patients may be assessed for the cost of the test, and also indicating the assay’s experimental nature.

Now, because of a June 1, 2011 FDA document, most IVD distributors prefer not to ship RUO or IUO kits in the US, rendering them unavailable except when used non-diagnostically in clinical trials. The Europace article posted here on May 9 and reposted below references the new assays, implying perhaps they are available, however US laboratory directors should be aware that they may be restricted. Here is the FDA statement:

Commercially Distributed In Vitro Diagnostic Products Labeled for Research Use Only or Investigational Use Only: Frequently Asked Questions

Here is the 2013 Europace article:

Europace 2013

I hope this is helpful, and I also hope the FDA review process for the new assays moves efficiently so we can soon meet clinical demands. Geo.

Comments (1)
Anticoagulant Therapy
George Fritsma
Jun 11, 2013 8:30am

Dave McGlasson gave me permission to excerp
Dave McGlasson gave me permission to excerpt a comment he posted to MEDLAB-L. His comment amplifies this post:
We thought it was unnecessary to monitor low molecular weight heparin at one time and then the ill-fated Ximelagatran before it started to “eat” up livers.  We should monitor the new oral anticoagulants in the following settings:
> When hemorrhaging occurs and the cause needs to be determined, for instance, ER presentation with adverse events.
> Risks: age >75, obese, poor renal or liver function.
> Drug interferences: Coumadin; heparinoids, amiodarone
> Unexpected responses to medication
What to monitor with? This is one question. Another is how do you reverse it?  Check recent ISMP reports on the number of bleeds with the new oral anticoagulants and the issues involved.  It is naïve to believe that we give out anticoagulant drugs that do not require any type of monitoring. We are dealing with “real world issues” not the monopathology seen in clinical trials. When dosing information is lacking, testing for the presence of these meds is extremely important in reversing their effects.

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