Effect of Voriconazole or Itraconazole on the Plasma Concentrations of Tacrolimus in Lung Transplant Recipients

ABSTRACT

OBJECTIVE: This study was performed to compare the changes in the blood concentrations of tacrolimus when either itraconazole or voriconazole is together with tacrolimus to prevent or treat invasive aspergillus pneumonia (IAP) in patients with lung transplants. Therefore we can compare the degree of drug-drug interactions between tacrolimus and itraconazole against tacrolimus and voriconazole. METHODS: Patients who were admitted and had lung transplants in a territory referral hospital from September 2012 to May 2015 were analyzed retrospectively. The effects of itraconazole and voriconazole on the plasma concentrations of tacrolimus were analyzed. RESULTS: Mean tacrolimus concentrations was 10.49±2.35 ng/mL vs. 10.95±2.98 ng/mL (p=0.722), and mean concentration of tacrolimus over the dose of tacrolimus per day was 8.510±5.890 (ng/mL)/(mg/d) vs. 15.45±28.47 (ng/mL)/(mg/d) (p=0.947) in itraconazole vs. voriconazole group each. The ratio of the number of the results out of target tacrolimus concentrations to the total number of tacrolimus concentration results was 18.0±13.3% vs. 24.4±18.5% (p=0.185). CONCLUSION: There were no significant differences between itraconzaole and voriconazole to have influences on mean concentrations of tacrolimus over tacrolimus dose per weight per day. However voriconazole tended to raise tacrolimus plasma concentrations more than itraconazole. Safer and more effective drug management to prevent and treat fungal infections should be done by therapeutic drug monitoring not only of tacrolimus but of itraconazole and voriconazole in lung transplant patients.