Monitor levels of antifungal drug, 5-fluorocytosine.
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).
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.
Ambient: 2 hours; Refrigerated: 24 hours; Frozen: 1 week
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.
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.
|Component Test Code*||Component Chart Name||LOINC|
|0060857||Antifungal Level, 5-Fluorocytosine, 5-FC||3639-2|
- 5-Flucytosine level
- 5-Flucytosine, Serum
- Ancobon serum levels
- Antimicrobial Assay, 5-Flucytosine
- Fluorocytosine antifungal level