Itraconazole Bioassay

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The MVista® Itraconazole bioassay test aids in monitoring antifungal therapy.

Bioassay

The result is not intended to be used as the sole means for clinical diagnosis or patient management decisions.

• – The bioassay is not accurate if the patient has taken another antifungal agent concurrently or within the prior week.
• – Concentration determined on a single specimen may not reflect future concentrations because of changes in adherence, drug dosage, route of administration, absorption, or receipt of other medication affecting absorption or metabolism of the azole.

• Serum: Collect serum specimens in serum separator or red top tube. Allow blood to clot for 30 minutes, then centrifuge. Pipette serum into a plastic screw cap vial.
• Plasma: Collect plasma specimens in an EDTA or heparin tube. Centrifuge for 15 minutes and pipette plasma into a plastic screw cap vial.

Serum/Plasma: 0.25 mL

Room Temperature/Refrigerated/Frozen: 7 days

Any specimen type other than serum or plasma.

Refrigerated/Frozen

Ship on dry ice or frozen cool pack for next day service. Monday – Friday delivery.

Testing performed on Wednesday. Results released the next morning.

Serum/Plasma: 2 days

Therapeutic ranges have not been established, but levels of at least 2.0 µg/mL have been recommended for treatment.

• None Detected: Reported when there is no zone of inhibition.
• <0.3 µg/mL: Reported when the zone of inhibition is smaller than that of the lowest calibrator.
• Positive: 0.3 – 20.0 µg/mL
• >20.0 µg/mL: Reported when the zone of inhibition is greater than the highest calibrator.

• – Follow-up testing may be necessary if there are changes in treatment, including starting or stopping interacting medications, or suspicion of treatment failure.
• – Drug levels should be measured after treatment, of at least 2 weeks in dogs and 3 weeks in cats, to reach a steady state.
• – Preferable to collect blood sample at trough time.