Itraconazole and Metabolite (Sendout)

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General Information

Lab Name
Itraconazole and Metab.
Lab Code
RITCOG
Epic Name
Itraconazole and Metab
External Test Id
ITCON
Description

Useful For:

  • Verifying systemic absorption of orally administered itraconazole
  • Patients with life-threatening fungal infections
  • Patients considered at risk for poor absorption or rapid clearance of itraconazole

Collection Timining: Trough level (immediately before the next dose) is recommended.

References
Synonyms
Hydroxyitraconazole, ITCON, Itraconazole Antimicrobial Assay, Sporanox
Components
Code Name
RITRA Itraconazole
RHTRA Hydroxyitraconazole

Interpretation

Method

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

Reference Range
See individual components
Ref. Range Notes

Reference Values:

Itraconazole (Trough):

Localized infection: >0.5 mcg/mL
Systemic infection: >1 mcg/mL

Hydroxyitraconazole: No therapeutic range established; activity and serum concentration are similar to parent drug.

Interpretation: A lower cutoff concentration has not been defined that applies in all cases. The serum concentration must be interpreted in association with other variables, such as the nature of the infection, the specific microorganism, and minimal inhibitory concentration results, if available. Localized infections are more likely to respond when serum itraconazole is more than 0.5 mcg/mL (by high-performance liquid chromatography); systemic infections generally require drug concentrations more than 1.0 mcg/mL. Consider target of more than 1.5 mcg/mL for itraconazole plus hydroxyitraconazole. Therapeutic drug monitoring should be done at steady state, which usually occurs in about 7 days. Timing of the serum collection is not as critical due to the drug's long half-life, but trough collections are recommended.

Interferences and Limitations

Cautions:

Enteropathy, H2-histamine receptor blockers, hepatic enzyme inducers, and other variables can result in low to non-detectable serum levels with concomitant high risk of therapeutic failure.

Patients with AIDS and organ transplant recipients receiving immunosuppressive therapy tend to have lower serum itraconazole levels on standard doses and are thus at high risk of therapeutic failure.

References

Ordering & Collection

Specimen Type
Blood
Collection

3 mL blood in RED TOP tube

Unacceptable: Any other sample type, including GOLD SST/Gel separator tube.

Handling Instructions

Outside Laboratories: Centrifuge sample and transfer serum to a separate plastic vial within 2 hours of collection. Freeze serum at -20°C while awaiting shipment. Transport on dry ice.

Stability: Frozen: 29 days; Refrigerated: 29 days; Ambient: 29 days.

Reject Due To: Serum from SST tube. Gross hemolysis, gross lipemia, and gross icterus are acceptable.

Quantity
Requested: 1 mL serum
Minimum: 0.2 mL serum

Processing

Receiving Instructions

Centrifuge sample and transfer serum to a separate plastic vial within 2 hours of collection. Freeze serum at -20°C.

Sendouts:

  • Order Mayo Test: ITCON
  • Interfaced: Yes [Interface: 601; Worksheet: MAFZ]

Stability: Frozen: 29 days; Refrigerated: 29 days; Ambient: 29 days.

Reject Due To: Serum from SST tube. Gross hemolysis, gross lipemia, and gross icterus are acceptable.

Misc Sendout

Performance

Lab Department
Sendouts Mayo Lab (FZ)(MAFZ)
Frequency
Performed: Monday through Saturday. Reported: 1-3 days from sample receipt at Mayo Clinic Labs.
Available STAT?
No
Performing Location(s)
Sendout Mayo Clinic Laboratories (Superior Drive)
800-533-1710

3050 Superior Drive NW
Rochester, MN 55901

Billing & Coding

CPT Codes
80189
LOINC
10989-2