Optimization of Micafungin Dosage for Chinese Patients with Sepsis in the Intensive Care Unit Based on a Population Pharmacokinetic-Pharmacodynamic Analysis.

PURPOSE: This study aimed to identify parameters that influence micafungin pharmacokinetics in Chinese patients with sepsis in the intensive care unit and optimize micafungin dosage by determining the probability of reaching pharmacodynamic targets. METHODS: Blood samples were collected from 32 Chinese patients with sepsis who were treated with micafungin. The samples were analyzed and used to build a population pharmacokinetic model. Monte Carlo simulations were performed to estimate the probability of achieving adequate plasma levels of micafungin against Candida species. RESULTS: Alanine aminotransferase and sequential organ failure assessment score were found to significantly influence the clearance and peripheral distribution volume of micafungin, respectively. Monte Carlo simulations based on area under the plasma concentration-time curve over 24 h showed that patients must be administered at least 200 and 250 mg micafungin daily to reach minimum inhibitory concentration breakpoints of 0.032 and 0.064 mg/L for Candida glabrata and Candida tropicalis, respectively. Additionally, a probability of target attainment of ≥ 90% could not be achieved for Candida krusei or Candida parapsilosis with a 300 mg daily dose. CONCLUSIONS: The recommended daily dose of micafungin (100 mg) may produce low clinical success ratios in non-Candida albicans infections; therefore, higher doses should be administered to improve clinical outcomes.

Clinical and pharmacoeconomic evaluation of antifungal prophylaxis with continuous micafungin in patients undergoing allogeneic stem cell transplantation: A six-year cohort analysis.

BACKGROUND: Patients undergoing allogeneic stem cell transplantation (aSCT) are at high risk to develop an invasive fungal disease (IFD). Optimisation of antifungal prophylaxis strategies may improve patient outcomes and reduce treatment costs. OBJECTIVES: To analyse the clinical and economical impact of using continuous micafungin as antifungal prophylaxis. PATIENTS/METHODS: We performed a single-centre evaluation comparing patients who received either oral posaconazole with micafungin as intravenous bridging as required (POS-MIC) to patients who received only micafungin (MIC) as antifungal prophylaxis after aSCT. Epidemiological, clinical and direct treatment cost data extracted from the Cologne Cohort of Neutropenic Patients (CoCoNut) were analysed. RESULTS: Three hundred and thirteen patients (97 and 216 patients in the POS-MIC and MIC groups, respectively) were included into the analysis. In the POS-MIC and MIC groups, median overall length of stay was 42 days (IQR: 35-52 days) vs 40 days (IQR: 35-49 days; p = .296), resulting in median overall costs of €42,964 (IQR: €35,040-€56,348) vs €43,291 (IQR: €37,281 vs €51,848; p = .993), respectively. Probable/proven IFD in the POS-MIC and MIC groups occurred in 5 patients (5%) vs 3 patients (1%; p = .051), respectively. The Kaplan-Meier analysis showed improved outcome of patients in the MIC group at day 100 (p = .037) and day 365 (p < .001) following aSCT. CONCLUSIONS: Our study results demonstrate improved outcomes in the MIC group compared with the POS-MIC group, which can in part be explained by a tendency towards less probable/proven IFD. Higher drug acquisition costs of micafungin did not translate into higher overall costs.

Assessment of micafungin loading dosage regimens against Candida spp. in ICU patients by Monte Carlo simulations.

OBJECTIVE: To assess the efficacy of loading dose on micafungin by simulating different dosage regimens. METHODS: A published study of micafungin in ICU patients was employed to simulate nine different dosage regimens which were sorted out three groups in terms of three maintenance doses. Using pharmacokinetic parameters and pharmacodynamic data, 5000-subject Monte Carlo simulations were conducted to simulate concentration-time profiles of micafungin, calculate probabilities of target attainment (PTAs), and cumulative fractions of response (CFRs) in terms of AUC/MIC targets. PTAs were calculated using AUC/MIC cut-offs: 285 (Candida parapsilosis), 3000 (all Candida spp.), and 5000 (non-parapsilosis Candida spp.). PTA or CFR > 90% was considered optimal for a dosage regimen. RESULTS: The concentration-time profiles of micafungin-simulated dosage regimens were obtained. PTA values were over 90% while applying the loading dose in each group of regimens: for Candida albicans and Candida glabrata (AUC/MIC = 5000), all regimens with loading dose provided PTAs of ≥ 90% for MIC ≤ 0.008 mg/L. The PTAs (AUC/MIC = 3000) were over 90% for MIC ≤ 0.008 mg/L in any regimen. However, for MIC inferior to 0.016 mg/L, only loading dosage regimens provided PTAs exceeding 90%. For C. parapsilosis (AUC/MIC = 285), the maximum MIC of achieving a PTA ≥ 90% was 0.25 mg/L both in the regimens of B (150 mg maintenance dose) and C (200 mg maintenance dose) with loading dose. In addition, CFR of any regimen with loading dose was ≥ 90% against C. albicans and C. glabrata. None of the dosage regimens achieved an expected CFR against C. parapsilosis. CONCLUSIONS: The dosage regimen of micafungin which had a loading dose of 1.5 times was more suitable for ICU patients infected by Candida spp.

Drug-Induced Liver Injury (DILI) With Micafungin: The Importance of Causality Assessment.

Background: Micafungin is increasingly used in the treatment and prevention of candidiasis in hospitalized patients. Limited data are available from which to assess the risk of drug-induced liver injury (DILI) with micafungin. No studies, to date, have applied a standardized causality assessment method to the study of micafungin-associated DILI. Objective: This study aimed to identify the frequency and clinical pattern of DILI in micafungin-treated patients as determined using 2 standardized causality assessment algorithms. Methods: A retrospective analysis was conducted of micafungin-treated patients at a single center between May 15, 2017, and May 15, 2018. DILI was defined on the basis of liver test elevations and the presence of associated signs and symptoms. The Roussel UClaf Causality Assessment Method (RUCAM) and the Naranjo algorithm were applied to each case. Results: A total of 99 patients were assessed; 52 were excluded, with a final sample of 47 evaluable patients. The definition of DILI was met in 9 (19%) patients, with a clinical pattern consistent with cholestatic injury in 7 of 9 (78%) patients. No cases were associated with jaundice. Agreement between the 2 causality assessment methods occurred in 4 of 9 (44%) cases. Application of the RUCAM algorithm led to the exclusion of 4 cases, resulting in a final reported prevalence of micafungin-associated DILI of 10.6%. Conclusion and Relevance: Asymptomatic DILI was identified in 10.6% of micafungin-treated patients. The choice of a causality assessment nomogram substantially influenced the determination of DILI prevalence. Compared with the Naranjo algorithm, the RUCAM algorithm is recommended as a more precise tool of assessing the relationship between drug exposure and DILI.

Assessment of the anti-biofilm effect of micafungin in an animal model of catheter-related candidemia.

In cases where catheter-related candidemia (CRC) must be managed without catheter withdrawal, antifungal lock therapy using highly active anti-biofilm (HAAB) agents is combined with systemic treatment. However, the activity of HAAB agents has never been studied in in vivo models using bioluminescence. We assessed the efficacy of micafungin using a bioluminescent Candida albicans SKCA23-ACTgLuc strain in an animal model of CRC. We divided 33 female Wistar rats into five groups: sham (A), infected nontreated (B), treated with lock therapy (0.16 mg/ml) (C), systemically treated only (1 mg/kg) (D), and systemically treated+lock (E). Catheters were colonized 24 h before insertion into the femoral vein (day 0). Treatment started on day 1 and lasted 7 days, followed by 7 days of surveillance. Bioluminescence assays were carried out on days 1, 3, 5, and 14, together with daily monitoring of clinical variables. Postmortem microbiological cultures from the catheter and several tissue samples were also obtained. Overall, 28 rats (84.8%) completed the study. Group B animals showed significant weight loss at days 2, 4, and 5 compared with groups C and D (P < .05). In group B, no animals survived after day 7, 75% had CRC, and bioluminescence remained constant 5 days after catheter implantation. Positive catheter culture rates in groups C, D, and E were, respectively, 83.3%, 62.5%, and 25.0% (P = .15). Micafungin proved to be a HAAB agent when administered both systemically and in lock therapy in an animal model of CRC, although the bioluminescence signal persists after treatment. This persistence should be further analyzed.

Pharmacokinetics of extended dose intervals of micafungin in haematology patients: optimizing antifungal prophylaxis.

Background: Extended dosing intervals for micafungin could overcome the need for hospitalization for antifungal prophylaxis. Objectives: This multicentre, open-label, randomized trial compared the pharmacokinetics of 300 mg of micafungin given twice weekly with 100 mg once daily as antifungal prophylaxis in adult haematology patients at risk of developing invasive fungal disease. Secondary objectives were assessment of adequate exposure with an alternative dosing regimen of micafungin (700 mg once weekly) through Monte Carlo simulations and assessment of safety in this patient population. Patients and methods: Twenty adult patients were randomized to receive either 300 mg of micafungin twice weekly or 100 mg once daily for 8 days. Blood samples were drawn daily and pharmacokinetic curves were determined on days 4/5 and 8. Monte Carlo simulations were performed for both investigated regimens as well as a frequently proposed alternative regimen (700 mg once weekly). Results: The predicted median AUC0-168h (IQR) for a typical patient on the investigated regimens of 100 mg once daily and 300 mg twice weekly and the hypothetical regimen of 700 mg once weekly were 690 (583-829), 596 (485-717) and 704 (585-833) mg·h/L, respectively. Conclusions: We observed comparable exposure with 300 mg of micafungin twice weekly and 100 mg of micafungin once daily. We provide the pharmacokinetic proof for an extended dosing regimen, which now needs to be tested in a clinical trial with hard endpoints.

Economic evaluation of micafungin versus liposomal amphotericin B (LAmB) for treating patients with candidaemia and invasive candidiasis (IC) in Turkey.

Micafungin was reported to be non-inferior to liposomal amphotericin B (LAmB) in treating patients with candidaemia and invasive candidiasis (IC). The current study aimed to evaluate the economic impact of using micafungin versus LAmB for treatment of candidaemia and IC in Turkey. A decision analytic model, which depicted economic consequences upon administration of micafungin or LAmB for treating patients with candidaemia and IC in the Turkish hospitals, was constructed. Patients were switched to an alternative antifungal agent if initial treatment failed due to mycological persistence. All patients were followed up until treatment success or death. Outcome probabilities were obtained from published literature and cost inputs were derived from the latest Turkish resources. Expert panels were used to estimate data that were not available in the literature. Cost per patient treated for each intervention was then calculated. Sensitivity analyses including Monte Carlo simulation were performed. For treatment of candidaemia and IC, micafungin (€4809) was associated with higher total cost than LAmB (€4467), with an additional cost of €341 per treated patient. Cost of initial antifungal treatment was the major cost driver for both comparators. The model outcome was robust over a wide variation in input variables except for drug acquisition cost and duration of initial antifungal treatment with micafungin or LAmB. LAmB is cost-saving relative to micafungin for the treatment of candidaemia and IC from the Turkish hospital perspective, with variation in drug acquisition cost of the critical factor affecting the model outcome.

Micafungin antifungal prophylaxis in children undergoing HSCT: can we give higher doses, less frequently? A pharmacokinetic study.

Background: Micafungin has a distinct advantage for antifungal prophylaxis in HSCT owing to its better safety profile, specifically in terms of hepatic and renal toxicity. In children, prophylactic micafungin is given as either 1 mg/kg every day or 3 mg/kg every other day. Objectives: We performed a prospective single-centre observational study that investigated the pharmacokinetics (PK) of a single 5 mg/kg dose of micafungin in young children undergoing HSCT, to ascertain the eventual feasibility of twice-weekly prophylactic administration. Methods: Nine children, ≤10 years of age undergoing HSCT, were enrolled and received a single intravenous dose of 5 mg/kg micafungin. Blood samples were obtained for PK analysis. Micafungin plasma concentration of >0.2 mg/L was chosen for target attainment (i.e. considered adequate prophylactic concentration). In addition, a population PK model was developed based on current and our previous PK study data. We also evaluated PK model-based simulation of PK profiles and target attainment using Monte Carlo simulation, for several dosing scenarios. Results: Mean clearance was 15.3 mL/h/kg (range 11.0-21.4 mL/h/kg) and the mean elimination half-life was 11.6 h (range 7.8-16.6 h). The mean concentration at 96 h was 0.11 mg/L (range 0.03-0.26 mg/L). Eleven percent (n = 1) of patients achieved target attainment at the end of 96 h. Simulation data showed that 1 mg/kg daily dosing and 3 mg/kg alternate-day dosing strategies achieved at least 99% and 81% target attainment, respectively, whereas a 5 mg/kg with 3 day-interval dosing strategy resulted in 64%, 72% and 84% target attainments in patients with body weights of 10, 20 and 30 kg, respectively. Conclusions: Micafungin at 5 mg/kg dosing did not achieve target attainment at the end of 96 h for antifungal prophylaxis in children undergoing HSCT. Simulation data suggest that a dosing strategy of micafungin at 5 mg/kg every 72 h is more likely to achieve target attainment in children with a higher body weight in comparison with children with a lower body weight. A cautious approach is advisable when using a high, but less frequent, dosing strategy in very young children.