Potential use of a simplified method for determination of itraconazole levels in plasma and esophageal tissue by using high-performance liquid chromatography

Abstract

A simplified high-performance liquid chromatography assay was developed for determination of itraconazole levels in plasma and esophageal tissue in four patients with AIDS who had been receiving daily oral doses of 100 mg of itraconazole in solution for at least 3 weeks for therapy of esophageal candidiasis. Itraconazole levels were about three times higher in esophageal tissue than in plasma (means +/- standard errors of 0.69 +/- 0.50 micrograms/g and 0.24 +/- 0.16 micrograms/ml, respectively; P = 0.04). This method is quick (it requires only 1 h for completion) and sensitive (the limits of detectability for itraconazole in plasma and esophageal tissue are 0.005 micrograms/ml and 0.01 micrograms/g, respectively), and it can be reliably used in clinical and research settings (accuracy, > 95%; absolute recovery from biological samples, 80 to 90%; coefficient of variation, 3.3 to 6.6%).