Posaconazole, Quantitative by LC-MS/MS
Also known as: POSACON AF
Use
Posaconazole is a triazole antifungal drug indicated to treat invasive aspergillus and candidiasis infections. Monitoring posaconazole levels helps optimize drug therapy and assess patient adherence. This test measures posaconazole concentration in the blood to ensure the levels are within the therapeutic range, which is crucial as the pharmacokinetics of posaconazole can be influenced by drug-drug interactions especially with those metabolized by UDP-glucuronosyltransferase. Posaconazole is also a known inhibitor of the cytochrome P450 3A4 enzyme.
Special Instructions
For accurate results, timing of specimen collection is crucial. Pre-dose (trough) draw should be conducted at the steady state concentration. Additionally, blood levels may be affected by other medications, patient conditions, and fat intake at dosing.
Limitations
Results can be influenced by concurrent medications, patient-specific factors, and dietary intake. As with all therapeutic drug monitoring, clinical correlation and judgment are essential. The test should not be used as the sole indicator of treatment efficacy or patient compliance. Unacceptable specimens include whole blood, gel separator tubes, light blue (citrate), or yellow (SPS or ACD solution) tubes.
New York Approved
Methodology
Mass Spectrometry
Biomarkers
LOINC Codes
- 53731-6
Result Turnaround Time
1-6 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.6 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Separate from cells ASAP or within 2 hours of collection, then freeze.
Patient Preparation
Pre-dose (trough) draw, at steady state concentration.
Storage Instructions
Frozen.
Causes for Rejection
Whole blood; gel separator tubes, light blue (citrate), or yellow (SPS or ACD solution).
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 48 hours |
| Frozen | 6 months |