Oral itraconazole vs oral voriconazole for CPA maintenance therapy

Submitted by MeganB on 26 April 2019

Chronic pulmonary aspergillosis (CPA) is a serious lung infection caused by the fungus Aspergillus; the disease has a low five-year survival rate and treatment options are limited. Currently the azoles voriconazole, itraconazole, posaconazole and isavuconazole are the mainstay of long-term CPA treatment, with oral voriconazole and itraconazole recommended for first-line maintenance treatment.

Dr Masato Tashiro and colleagues recently performed a retrospective study of CPA patients from two previous multicentre trials in Japan, in order to compare the efficacy of oral itraconazole and voriconazole for CPA maintenance treatment. Patients from the previous trials were diagnosed with CPA and commenced on intravenous antifungal treatment for 2-4 weeks, before being transferred to oral itraconazole or voriconazole as maintenance therapy.

Key points found:

• Patients prescribed voriconazole were more likely to show clinical improvement than those prescribed itraconazole (18.2% vs. 40.0%)
• When patients who improved were combined with stable patients in each group, the percentages were similar (50.9% for itraconazole and 52.6% for voriconazole)
• Patients prescribed itraconazole were more likely to be readmitted to hospital
• Patients prescribed itraconazole were more likely to be switched to a different azole due to insufficient efficacy of their first therapy
• The number of patients discontinuing treatment due to adverse effects was similar in both groups (20.3% for itraconazole vs 18.8% for voriconazole)
• There were no significant intergroup differences in mortality at the end of the observation period, in spite of the difference in the clinical efficacy of the two drugs

In this study the average dosage of itraconazole was lower than recommended, and most patients were not given the recommended form (oral solution); this puts the itraconazole group at a disadvantage when comparing clinical efficacy. This may be due to concerns about side effects, as monitoring of therapeutic itraconazole levels was not possible. The authors note that, if the recommended dose and form of itraconazole were prescribed, it is possible that increased clinical efficacy may be accompanied by increased adverse effects.

In conclusion, oral voriconazole was more effective than itraconazole for CPA initial maintenance therapy, and reduced hospital readmissions. However, despite this improved efficacy, there was no difference in mortality rates. Choosing voriconazole instead of itraconazole may improve patient quality of life and reduce the costs associated with hospital admissions. The authors write that further trials are required to confirm these results.