Report of the UK Cystic Fibrosis Trust Antibiotic Working Group

• It is important to assess the clinical response after itraconazole withdrawal to assess whether it isstill beneficial (e.g., prevents relapse and is corticosteroid-sparing) [C].• For patients receiving itraconazole, liver function tests should be obtained before therapy andshould be repeated whenever there is any suspicion of liver dysfunction. Routine liver functiontesting after 1 month and then every 3–6 months if therapy continues should be considered [C].• Concomitant medications should be meticulously reviewed to avoid a drug-drug interaction anddoses of concomitant medications and itraconazole should be adjusted accordingly. This mayrequire determination of serum concentrations of concomitant drugs and/or itraconazole [C].• Determination of itraconazole concentrations should also be considered when there is a lack ofclinical response or if there is concern about adequate drug absorption or patient compliance.Blood should be drawn 4 hours after a dose; at steady state, achieved during the second week oftherapy, random samples may be useful [C].• For those whom antifungal therapy is indicated and there is evidence of poor absorption ofitraconazole, oral voriconazole could be considered as an alternative. The oral dosage schedule isas follows:• Children