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|Approval req'd?||Yes, ID Pharmacy (443-9421) must approve all requests for levels.|
|Performed by||Focus via Quest|
|Collection Instructions||In most cases, a single trough level of posaconazole should be adequate. This level should be drawn after at least seven days of posaconazole (steady state is 7-10 days) have been administered.
Posaconazole should be administered with food or nutritional supplement. The level should be drawn from 11-12 hours after the previous dose and less than one hour prior to the next dose. Peak levels should only be drawn in special circumstances.
Complete a MiraVista test requisition Click here for form and include the patient and dosing information. Attach it to a completed routine laboratory requisition and forward with sample to lab.
Submit form, sample and UCSF routine requisition including the name of the ID pharmacist who approved sending levels.
|Container type||Red top (Gold top unacceptable)|
|Amount to Collect||4 mL blood|
|Preferred volume||2 mL serum|
|Min. Volume||1 mL serum|
|UCSF Rejection Criteria||Submitted without pharmacist approval. Submitted in Gold top tube.|
|Processing notes||Freeze serum. Order Quest test # 16480X|
|Stability||Frozen 2 weeks|
|Turn around times||5-7 days.|
Posaconazole is a triazole antifungal agent with potent activity against yeasts and molds. It is considered an alternative treatment for zygomyces, invasive Aspergillus infections, Candida and other infections caused by pathogenic yeasts. Data is insufficient to recommend routine monitoring of posaconazole concentrations in clinical practice but may be considered in certain circumstances.
Indications for Posaconazole TDM
At this time there is insufficient data to recommend routine monitoring of posaconazole levels. Thus, posaconazole TDM should be restricted to use in patients with proven or highly suspected invasive fungal infections, who are anticipated to need the drug for > 14 days, who are currently receiving appropriate doses, and who:
1) have known or suspected gastrointestinal absorption abnormalities and are receiving oral posaconazole
2) are receiving other drugs that would likely have a significant interaction with posaconazole (e.g. phenytoin, rifabutin, carbamezapine) and cannot be discontinued without an adverse effect on patient care
3) are experiencing treatment failure of their fungal infection despite maximal therapy, and where a change to a non-posaconazole-based regimen is not feasible
4) are experiencing substantial hepatic toxicity (AST/ALT > 5 times upper limit of normal or total bilirubin > 3 mg/dl) while on posaconazole, with other potential causes ruled out.
|Last Updated||5/14/2012 10:58:44 AM|
If you have additional questions regarding this test, please call: 415-353-1667