Test Code FLUC 5-Flucytosine, Serum
Reporting Name
5-Flucytosine, SUseful For
Monitoring serum concentration during therapy
Evaluating potential toxicity
May be useful to evaluate patient compliance
Method Name
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Performing Laboratory

Specimen Type
SerumSpecimen Required
Preferred: Red top
Acceptable: Serum gel
Specimen Volume: 0.5 mL
Collection Instructions:
1. Serum for a peak level should be drawn 1 to 2 hours after oral dose or 30 minutes after intravenous infusion. Trough specimens should be drawn immediately prior to next scheduled dose.
2. Spin down within 2 hours of draw.
Specimen Minimum Volume
0.3 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 28 days | |
Ambient | 28 days | ||
Frozen | 28 days |
Reject Due To
Gross hemolysis | OK |
Gross lipemia | OK |
Gross icterus | OK |
Reference Values
Therapeutic concentration:
Peak >25.0 mcg/mL (difficult infections may require higher concentrations)
Toxic concentration:
Peak >100.0 mcg/mL
Day(s) and Time(s) Performed
Tuesday, Thursday, 9 a.m.
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
80299
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
FLUC | 5-Flucytosine, S | 3639-2 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
82741 | 5-Flucytosine, S | 3639-2 |
Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.