Plasma Concentration of Antifungal Agent Micafungin for Pediatric Living Donor Liver Transplantation

BACKGROUND

Pediatric living-donor liver transplantation (LDLT) candidates often receive long-term antibiotic treatment. Micafungin has been used as an antifungal agent after LDLT, but the adequate dose after pediatric LDLT was unknown. Here, we report micafungin blood concentrations after pediatric LDLT and discuss its safety and adequate dosing.

METHODS

Pediatric patients with data on micafungin concentrations after LDLT were identified. Those with surgical complications were excluded. All patients received standard tacrolimus-based immunosuppression. A micafungin dose of 1 mg/kg was administered once daily for 10 days starting on postoperative day (POD) 1. The trough and peak micafungin blood concentrations were evaluated on PODs 1, 4, 7, and 10. Beta D glucan levels and liver function tests were assessed to determine micafungin effectiveness and safety.

RESULTS

Ten patients were enrolled, with a median age of 1.2 years. The median graft vs body weight ratio was 2.7%. The primary diseases were biliary atresia (n = 7), Alagille syndrome (n = 2), and progressive familial intrahepatic cholestasis type 2 (n = 1). Mean peak micafungin levels were 4.47, 6.27, 5.47, and 5.47 µg/mL on PODs 1, 4, 7, and 10, respectively. Mean trough levels were 2.03, 1.88, and 2.66 µg/mL on PODs 4, 7, and 10, respectively. The micafungin half-lives were 13.7, 14.7, and 14.0 hours on PODs 4, 7, and 10, respectively. Beta D glucan levels were 4.4 pg/mL and 3.7 pg/mL before and after transplantation, respectively, indicating no significant difference (P = .3). No clinical fungal infections were observed.

CONCLUSION

Micafungin administration is safe and effective after pediatric LDLT.

Micafungin Population PK Analysis in Healthy and Septic Pigs: Can the Septic Porcine Model Predict the Micafungin PK in Septic Patients?

OBJECTIVES

To describe micafungin pharmacokinetic (PK) alterations of sepsis induced in piglets and to determine whether the porcine septic model is able to predict the PK of micafungin in septic patients at the plasma and peritoneal sites.

METHODS

From healthy (n = 8) and septic piglet group (n = 16), total micafungin concentrations were subject to a population PK analysis using Monolix®. Data from 16 septic humans patients from others studies was used to compare micafungin PK between septic piglets and septic patients.

RESULTS

Sepsis induced in piglets slightly alters the total clearance and the volume of distribution, while inter-compartment clearance is increased (from 3.88 to 5.74 L/h) as well as the penetration into peritoneal cavity (from 61 to 90%). In septic human patients, PK parameters are similar except for the Vd, which is corrected by an allometric factor based on the body weight of each species. Micafungin penetration into peritoneal cavity of humans is lower than in septic piglets (40 versus 90%).

CONCLUSIONS

The sepsis induced in the porcine model alters the PK of micafungin comparable to that in humans. In addition, micafungin PK is similar between these two species at the plasma level taking into account the allometric relationship of the body weight of these species on the central volume of distribution. The porcine septic plasma model would be able to predict the micafungin PK in the septic patients. However, further studies on peritoneal penetration are necessary to characterize this inter-species difference.

Pharmacokinetic/pharmacodynamics variability of echinocandins in critically ill patients: A systematic review and meta-analysis

WHAT IS KNOWN AND OBJECTIVE

Anidulafungin, caspofungin and micafungin are three widely used echinocandin drugs licensed for the treatment of invasive fungal infections, and their clinical use is widespread. To evaluate pharmacokinetic/pharmacodynamics variability of echinocandins in critically ill patients by comparing the differences in pharmacokinetic parameters between critically ill patients and healthy volunteers or general patients.

METHODS

MEDLINE, EMBASE, The Cochrane Library and Pubmed were searched from inception until 6 September 2018. Studies investigating the pharmacokinetic parameters of echinocandins in critically ill patients, healthy volunteers or general patients were included. Our primary outcomes included AUC0-24 h , Cmax and Cmin (24 hours). Two reviewers independently reviewed all titles, abstracts and text, and extracted data. We applied R software (R 2017) to conduct meta-analysis.

RESULTS AND DISCUSSION

Of 3235 articles screened, 17 studies were included in the data synthesis. Descriptive data from single-arm studies show that critically ill patients who received caspofungin had more stable AUC0-24 h than those who received anidulafungin and micafungin. The Cmax of critically ill patients who received caspofungin and micafungin was similar to healthy volunteers. However, the Cmax in critically ill patients who received anidulafungin was lower than in healthy volunteers. The Cmin and T1/2 of critically ill patients who received caspofungin were larger than in healthy volunteers. The Vd and CL of critically ill patients receiving anidulafungin and micafungin were larger than in healthy volunteers.

WHAT IS NEW AND CONCLUSION

This systematic review provides an analysis of the pharmacokinetic/pharmacodynamics variability of echinocandins in critically ill patients. Based on the limited data available, caspofungin has less pharmacokinetic/pharmacodynamics variability than anidulafungin and micafungin.

Physicochemical characterization of micafungin and anidulafungin for its nebulized administration

OBJECTIVE

To determine by experimentation whether micafungin and  anidulafungin possess physicochemical properties suitable for  nebulization.

METHOD

PH, osmolality, viscosity, density and chloride content were  determined by pH monitoring, osmometry, viscometry, densitometry  and potentiometry in two samples of different concentrations, 5 and 10  mg/mL each echinocandin. Results: The results obtained for micafungin solution were: pH 5.80 (0.14), osmolality 293.33 (1.53) mOsm/kg, chloride content  134.67 (0.58) mmol/L and density 1,009.4 (0,1) kg/m3; while for 10  mg/mL solution: osmolality 342.00 (1.00) mOsm/kg, chloride content  139.67 (0.58) mmol/L and density 1,014.5 (0.2) kg/m3. The results  obtained for 5 mg/mL anidulafungin were: pH 4.22 (0.01), osmolality  464.67 (2.52) mOsm/kg, chloride content 137.00 (0.00) mmol/L and  density 1,016.5 (0,2) kg/m3; while for 10 mg/mL solution: osmolality  656.33 (1.15) mOsm/kg, chloride content 132.00 (0.00) mmol/L and  density 1,029.8 (0.4) kg/m3. Conclusions: PH, osmolality, chloride content and density values  proved to be suitable for proper tolerability by nebulization.

Micafungin-Induced Hypoglycemia in a Patient With Type 1 Diabetes: A Case Report and Review of Literature

OBJECTIVE

Patients with type 1 diabetes mellitus (T1DM) are insulin dependent. Infection increases insulin resistance and subsequently increases insulin needs. We are reporting a case of a patient with T1DM and severe infection who has reduced insulin needs after starting micafungin therapy.

PARTICIPANT

A 29-year-old Hispanic woman with known history of long-standing, uncontrolled T1DM presented for evaluation of worsening dysphagia and dyspnea. She was found to have cervical necrotizing fasciitis extending into the mediastinum and required several debridement surgeries along with broad-spectrum antibiotics and antifungal therapy. She had uncontrolled diabetes with a glycosylated hemoglobin of 13.4% (18.8 mM) on admission. Her insulin requirements progressively increased as a result of worsening infection, continuous tube feeds, and multiple debridement surgeries. She was started on micafungin, a potent 1,3-β-D glucan synthase inhibitor, to broaden antimicrobial coverage when her insulin requirement decreased to zero for >48 hours. Right after discontinuation of micafungin and her switch to a different antifungal, insulin requirements increased back to her baseline needs.

RESULTS

This is a report of decreased insulin requirements in a patient with T1DM correlating with micafungin administration. The mechanism of micafungin-induced hypoglycemia is not yet established. Oral administration of linear 1,3-β-D glucan has been documented to decrease blood glucose levels significantly by inhibition of expression of sodium-glucose transporter 1 (SGLT1) in intestinal mucosa.

CONCLUSION

We hypothesize that micafungin may inhibit SGLT-1 function and decrease insulin requirements in patient with T1DM.

Influence of subinhibitory antifungal concentrations on extracellular hydrolases and biofilm production by Candida albicans recovered from Egyptian patients

BACKGROUND

Extracellular hydrolases (phospholipase, aspartyl protease and haemolysin) and biofilm production are considered as major virulence factors of the opportunistic pathogenic fungus Candida albicans. However, the impact of antifungal therapy on such virulence attributes is not well investigated. The common antifungal agents may disturb the production of secreted hydrolases as well as biofilm formation. Accordingly, this study addressed the effect of subinhibitory concentrations (sub-MICs) of selected antifungal agents on some virulence factors of C. albicans clinical isolates.

METHODS

C. albicans isolates (n = 32) were recovered from different clinical samples and their identification was confirmed to the species level. Antifungal susceptibility profiles of isolates were determined against (nystatin, fluconazole and micafungin) and minimum inhibitory concentrations (MICs) were interpreted according to Clinical and Laboratory Standards Institute guidelines. Virulence determinants comprising secreted hydrolases (phospholipase, aspartyl protease and haemolysin) and biofilm formation were investigated in the presence of the sub-MICs of the tested antifungal agents.

RESULTS

Treatment of clinical C. albicans isolates with subinhibitory nystatin, fluconazole and micafungin concentrations significantly decreased production of extracellular hydrolases. Nystatin had the greatest inhibitory effect on phospholipase and aspartyl protease production. However, micafungin showed the highest reducing effect on the hemolytic activity of the treated clinical isolates. Moreover, nystatin and micafungin, but not fluconazole, had a noticeable significant impact on inhibiting biofilm formation of C. albicans clinical isolates.

CONCLUSION

Our findings highlighted the significant influences of commonly prescribed antifungal agents on some virulence factors of C. albicans. Accordingly, antifungal therapy may modulate key virulence attributes of C. albicans.