Use of antifungal agents in pediatric and adult high-risk areas

Adverse Drug Reactions with Antifungals Used in the Management of COVID-19 Associated Rhino-Orbito-Cerebral Mucormycosis

Background:

Amidst the second wave of the coronavirus disease 2019 (COVID-19) pandemic in India, there was a sharp increase in the number of cases of Rhino-orbito-cerebral mucormycosis (ROCM) leading to increased use of systemic antifungal agents namely Amphotericin B Deoxycholate, Liposomal Amphotericin B, and Posaconazole thereby causing an increase in associated adverse drug reactions. This study aimed to determine the incidence and frequency of adverse drug reactions (ADRs), to study any factors contributing to the same, while also exploring the use of Amphotericin B Deoxycholate as a cheaper, safe alternative to Liposomal Amphotericin B.

Materials and Methods:

It was a cross-sectional observational study, with a study population of 50 conducted over three months after ethics approval. All adult patients admitted to a tertiary care center, in a metropolitan city of Maharashtra, diagnosed with Rhino-orbito-cerebral mucormycosis, with a history of previous COVID-19 infection and receiving antifungals for the treatment of the same were included in the study. Central drug standard control organization (CDSCO) ADR reporting forms were used to collect data.

Results:

Electrolyte disturbances mainly hypokalemia were the most frequently encountered ADR with both Amphotericin formulations (39/50; 20.31%) followed by pain at the injection site (33/50; 17.19%). Nephrotoxicity occurred slightly more frequently with Amphotericin B Deoxycholate (19/29; 65%), compared to Liposomal Amphotericin B (11/19; 57%), while Posaconazole was mainly associated with gastrointestinal (GI) disturbances and hepatotoxicity.

Conclusion:

Amphotericin B Deoxycholate was associated most with ADRs, hypokalemia, and pain at the injection site being the most frequent. However, concerning nephrotoxicity, both Amphotericin formulations showed only a modest difference. Posaconazole was associated with the least number of ADRs and had a favorable safety profile.

Isavuconazole and voriconazole inhibition of sterol 14α-demethylases (CYP51) from Aspergillus fumigatus and Homo sapiens

Here we report the first evaluation of isavuconazole inhibition of Aspergillus fumigatus CYP51 and thus sterol biosynthesis in the fungus. Voriconazole and isavuconazole both bound tightly to recombinant A. fumigatus CYP51 isoenzymes A and B (AfCYP51A and AfCYP51B) isolated in Escherichia coli membranes. CYP51 reconstitution assays confirmed that AfCYP51A and AfCYP51B as well as three AfCYP51A mutants known to confer azole resistance (G54W, L98H and M220K) were strongly inhibited by both triazoles. Voriconazole bound relatively weakly to purified Homo sapiens CYP51 (HsCYP51), unlike isavuconazole that bound tightly. However, isavuconazole was a relatively poor inhibitor of HsCYP51 activity, with an IC₅₀ value (half-maximal inhibitory concentration) of 25 µM, which was 55- to 120-fold greater than those observed for the A. fumigatus CYP51 enzymes, albeit not as poor an inhibitor of HsCYP51 as voriconazole with an IC₅₀ value of 112 µM. Sterol analysis of triazole-treated A. fumigatus Af293 cells confirmed that isavuconazole and voriconazole both inhibited cellular CYP51 activity with the accumulation of 14-methylated sterol substrates and depletion of ergosterol levels. Isavuconazole elicited a stronger perturbation of the sterol composition in A. fumigatus Af293 than voriconazole at 0.0125 µg/mL, indicating increased potency. However, complementation studies in Saccharomyces cerevisiae using strains containing AfCYP51A and AfCYP51B showed isavuconazole to be equally as effective at inhibiting CYP51 activity as voriconazole. These in vitro studies suggest that isavuconazole is an effective alternative to voriconazole as an antifungal agent against the target CYP51 in A. fumigatus.

Adverse Drug Reactions in Patients Receiving Systemic Antifungal Therapy at a High-Complexity Hospital

The aim of the present study was to determine the frequency of adverse drug reactions (ADRs) associated with the use of systemic antifungal drugs in patients hospitalized at a high-complexity hospital. In addition, factors associated with ADRs were investigated. This cross-sectional retrospective study involved the investigation of 183 medical records of patients receiving systemic antifungal therapy. Antifungal drugs were classified using the fourth level of the Anatomical Therapeutic Chemical System. ADR causality was classified using the Naranjo algorithm. Drug interactions were assessed using DRUG-REAX software. Data were analyzed with descriptive statistics and univariate and multivariate logistic regression. A total of 53 patients (29.0%) had at least 1 ADR involving antifungals. Ninety-six ADRs were detected. The main ADRs observed were an infusion reaction in 24 patients (25.0%), hypokalemia in 22 (22.9%), nephrotoxicity in 18 (18.7%), and hepatotoxicity in 15 (15.6%). Amphotericin B and voriconazole were associated with ADRs of major clinical impact. Eleven of the ADRs (11.4%) were related to drug interactions. The following 3 factors were contributors to the multivariate model for the occurrence of ADRs caused by antifungal drug use: neoplasm diagnosis (odds ratio [OR], 3.9; 1.9-7.9), length of hospital stay (OR, 2.2; 1.1-4.5), and the use of ≥13 drugs (OR, 3.4; 1.6-7.2). Our study revealed positive associations between the occurrence of ADRs and diagnosis of a neoplasm, the length of stay, and the use of multiple drugs concomitant with antifungals. These risk factors should be considered in antifungal stewardship, among other actions, to promote the rational use of antifungal agents.

Anti-Candida activity of 1-18 fragment of the frog skin peptide esculentin-1b: in vitro and in vivo studies in a Caenorhabditis elegans infection model

Candida albicans represents one of the most prevalent species causing life-threatening fungal infections. Current treatments to defeat Candida albicans have become quite difficult, due to their toxic side effects and the emergence of resistant strains. Antimicrobial peptides (AMPs) are fascinating molecules with a potential role as novel anti-infective agents. However, only a few studies have been performed on their efficacy towards the most virulent hyphal phenotype of this pathogen. The purpose of this work is to evaluate the anti-Candida activity of the N-terminal 1-18 fragment of the frog skin AMP esculentin-1b, Esc(1-18), under both in vitro and in vivo conditions using Caenorhabditis elegans as a simple host model for microbial infections. Our results demonstrate that Esc(1-18) caused a rapid reduction in the number of viable yeast cells and killing of the hyphal population. Esc(1-18) revealed a membrane perturbing effect which is likely the basis of its mode of action. To the best of our knowledge, this is the first report showing the ability of a frog skin AMP-derived peptide (1) to kill both growing stages of Candida; (2) to promote survival of Candida-infected living organisms and (3) to inhibit transition of these fungal cells from the roundish yeast shape to the more dangerous hyphal form at sub-inhibitory concentrations.