Azole plasma concentrations in lung transplant recipients

Background: The absorption of azoles is subject to a high inter- and intra-individual variability. However, therapeutic drug monitoring [TDM] is not routinely performed. The purpose of this observation was to analyse azole plasma levels [APL] in lung transplant recipients [LTR]. Methods: 116 LTR of our lung transplantation [LTx] follow-up program who underwent TDM (65 male, 84 double-LTx, 3.1±3.5 years after LTx, age 49.7±14.9 years, underlying disease [ULD]: idiopathic pulmonary fibrosis [IPF; n=34; 29%], cystic fibrosis [CF; n=29; 25%], chronic obstructive pulmonary disease [COPD; n=28; 24%], other [n=25; 22%]) were evaluated. The target plasma levels [TPL] of azoles were defined as follows: Itraconazole [ITR] and Voriconazole [VOR] >1000µg/L, Posaconazole [POS] >700µg/L. APL were assayed using high performance liquid chromatography. Results: The mean APL for ITR, VOR, and POS were 715.4±866.1µg/L, 1649.2±1300.5µg/L and 903.4±780.9µg/L, respectively. Most frequent use was noted for ITR (n=55; 47%). The following results are classified by azole and ULD: View this table: Conclusion: Our data suggest that TDM is important to identify patients at risk for sub-therapeutic APL. Therefore, measuring plasma concentrations should be considered as part of the best practice management following LTx.