Sign in →

Test Code ANCOBAN 5-Flucytosine, Serum

Additional Codes

Mayo Test ID
FLUC

Reporting Name

5-Flucytosine, S

Useful For

Monitoring serum concentration during therapy

 

Evaluating potential toxicity

 

May be useful to evaluate patient compliance

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type

Serum


Specimen Required


Container/Tube:

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 Frozen (preferred) 28 days
  Ambient  28 days
  Refrigerated  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 days

NY State Approved

Yes

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Northwell Health Laboratories Additional Information:

Computer Interface Code

   PDM # 5913400