title: Measurement of voriconazole in serum and plasma.
abstract: OBJECTIVE
  Voriconazole is an antifungal agent structurally related to fluconazole. While regular drug monitoring is not indicated in most patients, it may help guide dosing in patients with reduced hepatic/renal function, on concurrent therapy with drugs that affect CYP2C9, with altered CYP2C9 genotypes, or during adverse drug reactions. Here we describe an HPLC method for determination of voriconazole.
  
  
  METHODS
  Samples, calibrators and controls were extracted using a liquid/liquid extraction. Chromatographic separation achieved using gradient solvent delivery with detection at 254 nm with a run time of 10 min. Concentration was calculated by comparison of peak height ratio of the drug with that of internal standard (IS) against a standard curve.
  
  
  RESULTS
  The assay is linear from 0.29 to 57 micromol/L (0.1-20 microg/mL) shows good linearity (y=0.98x+0.36, r(2)=0.9978). The assay has inter- and intra-day precisions of <10%. The stability of the drugs in specimens was tested for up to 7 days at room temperature, for 30 days frozen at -20 degrees C, and through 3 freeze-thaw cycles and was found to be stable under those conditions.
  
  
  CONCLUSIONS
  This describes a robust method for the determination of voriconazole in serum and plasma.
authors.affiliation: Division of Clinical Biochemistry and Immunology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Hilton 730, 200 First Street SW, Rochester, MN 55905, USA. Langman.loralie@mayo.edu
authors.forename: Loralie J
authors.initials: LJ
authors.lastname: Langman
authors.forename: Felix
authors.initials: F
authors.lastname: Boakye-Agyeman
mesh_terms: D000925:Anticoagulants / Q000032:analysis / Q000737:chemistry; D000935:Antifungal Agents / Q000032:analysis / Q000097:blood; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004347:Drug Interactions; D016903:Drug Monitoring / Q000379:methods; D004355:Drug Stability; D006801:Humans; D008954:Models, Biological; D011743:Pyrimidines / Q000032:analysis* / Q000097:blood*; D044967:Serum / Q000737:chemistry*; D014230:Triazoles / Q000032:analysis* / Q000097:blood*; D065819:Voriconazole
chemical_list: D000925:Anticoagulants; D000935:Antifungal Agents; D011743:Pyrimidines; D014230:Triazoles; D065819:Voriconazole