Test ID: FARIX
Arixtra (Fondaparinux) Level
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Method Name A short description of the method used to perform the test
Anti-Xa Chromogenic
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Fondaparinux FORWARD
Fondaparinux Level FORWARD
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Draw blood in a light blue-top (sodium citrate) tube(s). Spin down and send 0.5 mL citrated plasma frozen in plastic vial.
Note: 1) Patient's Date of Birth is required.
2) The sample should be drawn 3 hours after injection of
drug in order to compare to published peak levels.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Specimens other than | Plasma |
| Anticoagulants other than | Sodium citrate |
| Hemolysis | Mild OK; Gross reject |
| Thawing | Warm reject: Cold reject |
| Lipemia | NA |
| Icteric | NA |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Plasma Na Cit | Frozen | |
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Units: mg/L
Test Performed by: BloodCenter of Wisconsin
638 N 18th Street
Milwaukee, WI 53233-2121
Interpretation Provides information to assist in interpretation of the test results
Interpretive comments: Dosing protocols for Arixtra have been validated by empiric clinical trials. The relationship between pharmacokinetic parameters and efficacy or safety (bleeding) has not been reported, nor have guidelines for target fondaparinux levels been published in the medical literature. Drug elimination half-life is approximately 17-21 hours in normal individuals, but is prolonged in patients with renal insufficiency. "Mean observed" drug levels are available from patients enrolled in clinical trials. In patients receiving daily injections of 2.5 mg (for DVT prophylaxis), the observed steady state mean peak level observed approximately 3 hours after injection was approximately 0.45 mg/L, with the
observed minimum mean steady state plasma level of approximately 0.17 mg/L before the next dose. In patients receiving 5-10 mg Arixtra (for treatment of DVT or pulmonary embolism), the observed mean steady state peak level averaged approximately 1.23 mg/L approximately 3 hours after injection, with the observed minimum mean steady state plasma concentration at 0.58 mg/L before the next dose. (Data taken from prescribing information for Arixtra, and from GlaxoSmithKline informational materials.)
Method Description Describes how the test is performed and provides a method-specific reference
Method: Plasma Arixtra (Fondaparinux) level is quantified by chromogenic anti-Factor Xa assay with calibration against
a reference curve constructed with fondaparinux. Results are expressed in milligrams/liter (mg/L). This assay is not
appropriate for monitoring of patients on unfractionated heparin or low molecular weight heparin drugs.
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Varies; Monday through Friday
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Performing Laboratory Location The location of the laboratory that performs the test
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
85130
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| Z2292 | Arixtra Level | In Process |
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