Antifungal Level, 5-Fluorocytosine (5-FC)
0060846
 
Ordering Recommendation
Mnemonic
ML 5-FLUOR
Methodology
Quantitative Bioassay
Performed
Sun-Sat
Reported
1-2 days
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
 
Collect
Plain red.  
Specimen Preparation
Aseptically remove 2 mL serum to a sterile tube (ARUP supply #43115) and freeze. Available online through eSupply using ARUP Connect™ or contact ARUP Client Services at (800) 522-2787. (Min: 1 mL).  
Storage/Transport Temperature
Frozen.  
Unacceptable Conditions
Plasma.  
Remarks
Required information includes: time and date of collection, time of last dose, and list of all antibiotics that the patient is receiving or has received in the past 48 hours.  
Stability
Ambient: 2 hours; Refrigerated: 24 hours; Frozen: 1 week  
Reference Interval
Interpretive Data
Normal peak serum concentration for 5-fluorocytosine is 30-45 µg/mL with a 2 g PO dose or 60-80 µg/mL with a 100 mg/kg/day PO dose. Trough serum concentration is not well established. Toxicity may be seen with sustained levels greater than 100 µg/mL.

For bioassay measurements, the presence of other antimicrobial agents may interfere with the assay. Other factors that may influence antimicrobial levels include inherent differences among patients and their underlying physical conditions as well as the dose and route of administration of the antimicrobial agent.
Note
Please include time of last dose, and list of all antibiotics that the patient is receiving or has received in the past 48 hours. This information is important for laboratory handling and essential for subsequent physician interpretation of results.
CPT Code(s)
80299
Components
Component Test Code*Component Chart Name
0060857Antifungal Level, 5-Fluorocytosine, 5-FC
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, contact interface support at interface.support@aruplab.com.
Cross References
  • 5-Flucytosine
  • 5-Flucytosine level
  • 5-Flucytosine, Serum
  • Ancobon serum levels
  • Antimicrobial Assay, 5-Flucytosine
  • Fluorocytosine antifungal level