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HelpTest Code ANCOBAN 5-Flucytosine, Serum
Additional Codes
| Mayo Test ID |
|---|
| FLUC |
Reporting Name
5-Flucytosine, SUseful For
Monitoring serum concentration during therapy
Evaluating potential toxicity
May be useful to evaluate patient compliance
Performing Laboratory
Mayo Clinic Laboratories in Rochester
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 |
|---|---|---|
| Serum | Refrigerated (preferred) | 28 days |
| Ambient | 28 days | |
| Frozen | 28 days |
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 | In Process |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 82741 | 5-Flucytosine, S | 3639-2 |
Clinical Information
Flucytosine is a broad-spectrum antifungal agent generally used in combined therapy (often with amphotericin B) for treatment of fungal infections such as cryptococcal meningitis. Concerns with toxicity (bone marrow suppression, hepatic dysfunction) and development of fungal resistance limit the use of flucytosine, particularly as a monotherapy. The drug is well-absorbed orally, but can also be administered intravenously (available outside of the United States).
There is good correlation between serum concentrations of flucytosine with both efficacy and risk for toxicity. Because of the drugs short half-life (3-6 hours), therapeutic monitoring is typically performed at peak levels, 1 to 2 hours after an oral dose or 30 minutes after an intravenous administration.
Flucytosine is eliminated primarily as unmetabolized drug in urine. Patients with renal dysfunction may require dose adjustments or more frequent monitoring to ensure that serum concentrations do not accumulate to excessive levels. Nephrotoxicity associated with use of amphotericin B can affect elimination of flucytosine when the drugs are coadministered.
Analytic Time
2 daysNY State Approved
YesMethod Name
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Computer Interface Code
PDM # 5913400