Mayo Test Catalog, (Sorted By Test Name) - Mayo Medical ...

FVORI
91998
VORI
88698
variants (less common), or Type 3 (rare)
Interpretation: An interpretive report will be provided when testing is complete.
Reference Values:
FACTOR VIII ACTIVITY
55-200%
von WILLEBRAND FACTOR ACTIVITY
55-200%
von WILLEBRAND FACTOR ANTIGEN
55-200%
Clinical References: 1. Federici AB, Mannucci PM: Advances in the genetics and treatment of
von Willebrand disease. Curr Opin Pediatr 2002 Feb;14(1):23-33 2. Budde U, Schneppenheim R: von
Willebrand factor and von Willebrand disease. Rev Clin Exp Hematol 2001 Dec;5(4):335-368 3. Kumar
S, Pruthi RK, Nichols WL: Acquired von Willebrand disease. Mayo Clin Proc 2002 Feb;77(2):181-187
Voriconazole
Reference Values:
Test Performed by: U.T. Health Science Ctr San Antonio
7703 Floyd Curl Drive
Department of Pathology
Fungal Lab
San Antonio, TX 78229-3900
Voriconazole, Serum
Clinical Information: Voriconazole (Vfend) is an antifungal agent approved for treatment of
invasive aspergillosis and candidemia/candidiasis, as well as for salvage therapy for infections in
patients refractory to or intolerant of other antifungal therapy. The drug inhibits the fungal enzyme
14a-sterol demethylase, a critical step in ergosterol biosynthesis. Voriconazole is metabolized in the
liver primarily by CYP2C19; CYP2C9 and CYP3A4 play limited roles. The primary metabolite is
voriconazole N-oxide, which has no antifungal activity. Drug clearance is primarily dependent on
hepatic metabolism. The pharmacokinetics of voriconazole is highly variable and nonlinear, which
results in an increased dose leading to a greater than proportional increase in serum concentration. The
bioavailability of oral voriconazole is >95%. Approximately 60% of the drug in serum is protein bound.
Voriconazole has a volume of distribution of 4.6 L/kg. Most (80%) of the drug is excreted in the urine,
exclusively as metabolites. Adverse effects of voriconazole include visual disturbances, skin rashes, and
elevated liver enzyme levels.
Useful For: Monitoring trough levels of voriconazole is suggested in individuals with reduced liver
function, individuals with CYP2C19 polymorphisms associated with poor metabolic function, patients
taking other medications that affect CYP2C19 activity, and in patients experiencing potential toxicity.
Monitoring trough levels may be reasonable in patients who are not responding optimally or have drug
interactions that may decrease voriconazole levels, or to ensure adequate oral absorption.
Interpretation: Trough levels >6 mcg/mL (and especially >10 mcg/mL) have been associated with
toxicity in several reports. Trough levels