The most commonly described technique, known as sparing, involves using an antifungal agent to clear spores from airways adjacent to corticosteroid therapy. The antifungal aspect aims to reduce fungal causes of bronchial inflammation, whilst also minimising the dose of corticosteroid required to reduce the immune system's input to disease progression. The strongest evidence (double-blinded, randomized, placebo-controlled trials) is for itraconazole twice daily for four months, which resulted in significant clinical improvement compared to placebo, and was mirrored in CF patients. Using itraconazole appears to outweigh the risk from long-term and high-dose prednisone. Newer triazole drugs—such as posaconazole or voriconazole—have not yet been studied in-depth through clinical trials in this context.