Infectious Disease. How to bolster the antifungal pipeline.

The burden of human disease related to medically important fungal pathogens is substantial. An improved understanding of antifungal pharmacology and antifungal pharmacokinetics-pharmacodynamics has resulted in therapeutic drug monitoring (TDM) becoming a valuable adjunct to the routine administration of some antifungal agents. TDM may increase the probability of a successful outcome, prevent drug-related toxicity and potentially prevent the emergence of antifungal drug resistance. Much of the evidence that supports TDM is circumstantial. This document reviews the available literature and provides a series of recommendations for TDM of antifungal agents.

Sensitization to fungi and long term or uncontrolled fungal infection are associated with poor control of asthma, the likelihood of more severe disease and complications such as bronchiectasis and chronic pulmonary aspergillosis. Modelling suggests that >6.5 million people have severe asthma with fungal sensitizations (SAFS), up to 50% of adult asthmatics attending secondary care have fungal sensitization, and an estimated 4.8 million adults have allergic bronchopulmonary aspergillosis (ABPA). There is much uncertainty about which fungi and fungal allergens are relevant to asthma, the natural history of sensitisation to fungi, if there is an exposure response relationship for fungal allergy, and the pathogenesis and frequency of exacerbations and complications. Genetic associations have been described but only weakly linked to phenotypes. The evidence base for most management strategies in ABPA, SAFS and related conditions is weak. Yet straightforward clinical practice guidelines for management are required. The role of environmental monitoring and optimal means of controlling disease to prevent disability and complications are not yet clear. In this paper we set out the key evidence supporting the role of fungal exposure, sensitisation and infection in asthmatics, what is understood about pathogenesis and natural history and identify the numerous areas for research studies.

To evaluate the efficacy and safety of voriconazole in acute invasive aspergillosis (IA), an open, noncomparative multicenter study was conducted. Immunocompromised patients with IA were treated with intravenously administered voriconazole 6 mg/kg twice a day (b.i.d.) twice and then 3 mg/kg b.i.d. for 6-27 days, followed by 200 mg b.i.d. administered orally for up to 24 weeks. Response was assessed by clinical and radiographic change. A total of 116 patients were assessable. IA was proven in 48 (41%) and probable in 68 patients. Voriconazole was given as primary therapy in 60 (52%). Good responses were seen in 56 (48%); 16 (14%) showed complete response and 40 (34%) partial response. A stable response was seen in 24 patients (21%), and 36 (31%) of the infections failed to respond to therapy. Good responses were seen in 60% of those with pulmonary or tracheobronchial IA (n=84), 16% with cerebral IA (n=19), 58% with hematologic disorders (n=67), and 26% of allogeneic stem cell transplant recipients (n=23). Voriconazole is efficacious in treating acute IA.