Antifungals: From Pharmacokinetics to Clinical Practice

Abstract

The use of antifungal drugs started in the 1950s with polyenes nystatin, natamycin and amphotericin B-deoxycholate (AmB). Until the present day, AmB has been considered to be a hallmark in the treatment of invasive systemic fungal infections. Nevertheless, the success and the use of AmB were associated with severe adverse effects which stimulated the development of new antifungal drugs such as azoles, pyrimidine antimetabolite, mitotic inhibitors, allylamines and echinochandins. However, all of these drugs presented one or more limitations associated with adverse reactions, administration route and more recently the development of resistance. To worsen this scenario, there has been an increase in fungal infections, especially in invasive systemic fungal infections that are particularly difficult to diagnose and treat. In 2022, the World Health Organization (WHO) published the first fungal priority pathogens list, alerting people to the increased incidence of invasive systemic fungal infections and to the associated risk of mortality/morbidity. The report also emphasized the need to rationally use existing drugs and develop new drugs. In this review, we performed an overview of the history of antifungals and their classification, mechanism of action, pharmacokinetic/pharmacodynamic (PK/PD) characteristics and clinical applications. In parallel, we also addressed the contribution of fungi biology and genetics to the development of resistance to antifungal drugs. Considering that drug effectiveness also depends on the mammalian host, we provide an overview on the roles of therapeutic drug monitoring and pharmacogenomics as means to improve the outcome, prevent/reduce antifungal toxicity and prevent the emergence of antifungal resistance. Finally, we present the new antifungals and their main characteristics.

Superficial Dermatophytosis across the World’s Populations: Potential Benefits from Nanocarrier-Based Therapies and Rising Challenges

“…Oral antifungals exhibit more serious adverse events as compared with topical formulations. Along with being costly, some of them can produce organ toxicity and show frequent drug–drug interactions . Griseofulvin, a generally used oral antimycotic agent, shows adverse effects like hepatotoxicity, photosensitivity, headache, nausea, and vomiting.…”

“…Along with being costly, some of them can produce organ toxicity and show frequent drug–drug interactions. 121 Griseofulvin, a generally used oral antimycotic agent, shows adverse effects like hepatotoxicity, photosensitivity, headache, nausea, and vomiting. Ketoconazole, along with hepatotoxicity, shows other side effects like impotence, hemolytic anemia, and abdominal pain.…”

Latin American Plants against Microorganisms

“…A 2017 review points out the importance of recognizing the pathways involved in fungal pathogenicity and identifying opportunity areas to create better antibiotics [69], even if knowing these factors would make it impossible to create efficient vaccines [70,71]. However, current antifungal drugs have different mechanisms of action (Table 3); the most common mechanisms are directed against the fungal cell wall or membrane, specifically against ergosterol or (1,3)-β-d-glucan biosynthesis, except for pyrimidines and orotomides that target crucial molecules in nucleic acid metabolism [72][73][74][75].…”

Optimization of the antifungal properties of the bacterial peptide EntV by variant analysis

“…Presently, there are only three broadly used classes of antifungals available, targeting ergosterol directly (polyenes), ergosterol synthesis (azoles), or the synthesis of cell wall β-glucan (echinocandins) ( 16 , 18 ). There is a dire need for novel antifungal agents exemplified by the continual increase in the clinical incidence of fungal pathogens that exhibit resistance to traditional antifungal agents ( 19 – 22 ).…”