Comparison of the Efficacy of Posaconazole Delayed Release Tablets and Suspension in Pediatric Hematology/Oncology Patients

Antifungal Prophylaxis With Posaconazole in Immunocompromised Children Younger Than 13 Years

OBJECTIVE

Prophylaxis with posaconazole (PP) is effective in the prevention of invasive fungal infections in immunocompromised adult patients. However, evaluation of its effectiveness and safety in children is limited. The aim of the study was to describe the use of posaconazole as antifungal prophylaxis in children.

METHODS

We reviewed the medical records of immunocompromised patients younger than 13 years with hematologic diseases and post hematopoietic stem cell transplant (HSCT) who received antifungal PP at the Instituto Nacional de Salud del Niño San Borja (INSN-SB) in Lima, Peru, from January 2014 to December 2018.

RESULTS

Fifty-six courses of PP were identified in 47 patients with a median age of 7.5 years (IQR, 4-10), 51.6% (n = 24) of whom were female. The main underlying medical conditions were aplastic anemia (n = 19, 33.9%), acute lymphoblastic leukemia (n = 18, 32.1%), acute myeloid leukemia (n = 14, 25.0%), and 34.1% had undergone HSCT. The median dose of posaconazole was 13.62 mg/kg/day (IQR, 12.0-16.8), and the median duration of PP was 24 days (IQR, 16-82). Gastrointestinal symptoms included abdominal pain (17.9%), nausea (16.1%), diarrhea (7.1%), and vomiting (3.6%). Elevated alanine aminotransferase and aspartate aminotransferase levels were observed in 9/35 patients (25.7%) and 10/51 (19.6%) patients, respectively. Five cases of breakthrough fungal infection were identified (8.9%).

CONCLUSIONS

Patients younger than 13 years who received PP showed an increase in transaminase values, and the development of breakthrough fungal infections.

Consensus guidelines for optimising antifungal drug delivery and monitoring to avoid toxicity and improve outcomes in patients with haematological malignancy and haemopoietic stem cell transplant recipients, 2021

Antifungal agents can have complex dosing and the potential for drug interaction, both of which can lead to subtherapeutic antifungal drug concentrations and poorer clinical outcomes for patients with haematological malignancy and haemopoietic stem cell transplant recipients. Antifungal agents can also be associated with significant toxicities when drug concentrations are too high. Suboptimal dosing can be minimised by clinical assessment, laboratory monitoring, avoidance of interacting drugs, and dose modification. Therapeutic drug monitoring (TDM) plays an increasingly important role in antifungal therapy, particularly for antifungal agents that have an established exposure-response relationship with either a narrow therapeutic window, large dose-exposure variability, cytochrome P450 gene polymorphism affecting drug metabolism, the presence of antifungal drug interactions or unexpected toxicity, and/or concerns for non-compliance or inadequate absorption of oral antifungals. These guidelines provide recommendations on antifungal drug monitoring and TDM-guided dosing adjustment for selected antifungal agents, and include suggested resources for identifying and analysing antifungal drug interactions. Recommended competencies for optimal interpretation of antifungal TDM and dose recommendations are also provided.

Potency and preclinical evidence of synergy of oral azole drugs and miltefosine in an ex vivo model of Leishmania (Viannia) panamensis infection

Failure of treatment of cutaneous leishmaniasis with antimonial drugs and miltefosine is frequent. Use of oral combination therapy represents an attractive strategy to increase efficacy of treatment and reduce the risk of drug resistance. We evaluated the potency of posaconazole, itraconazole, voriconazole and fluconazole, and the potential synergy of those demonstrating the highest potency, in combination with miltefosine (HePC), against infection with Leishmania (Viannia) panamensis. Synergistic activity was determined by isobolograms and calculation of Fractional Inhibitory Concentration Index (FICI), based on parasite quantification using an ex vivo model of human PBMCs infected with a luciferase-transfected, antimony and miltefosine sensitive line of L. panamensis. The drug combination and concentrations that displayed synergy were then evaluated for anti-leishmanial effect in 10 clinical strains of L. panamensis by qRT-PCR of Leishmania 7SLRNA. High potency was substantiated for posaconazole and itraconazole against sensitive as well as HePC and antimony resistant lines of L. panamensis, whereas fluconazole and voriconazole displayed low potency. HePC combined with posaconazole (Poz) demonstrated evidence of synergy at free drug concentrations achieved in plasma during treatment (2 μM HePC + 4 μM Poz). FICI, based on 70% and 90% reduction of infection, was 0.5 for the sensitive line. Combination of 2 μM HePC + 4 μM Poz effected significantly greater reduction of infection by clinical strains of L. panamensis than individual drugs. Orally administrable miltefosine/posaconazole combinations demonstrated synergistic anti-leishmanial capacity ex vivo against L. panamensis, supporting their potential as a novel therapeutic strategy to improve efficacy, and effectiveness of treatment.