Isavuconazole is a triazole antifungal agent recently recommended as first-line therapy for invasive pulmonary aspergillosis. With the COVID-19 pandemic, cases of COVID-19-associated pulmonary aspergillosis (CAPA) have been described with a prevalence ranging from 5 to 30%. We developed and validated a population pharmacokinetic (PKpop) model of isavuconazole plasma concentrations in intensive care unit patients with CAPA. Nonlinear mixed-effect modeling Monolix software were used for PK analysis of 65 plasma trough concentrations from 18 patients. PK parameters were best estimated with a one-compartment model. The mean of ISA plasma concentrations was 1.87 [1.29–2.25] mg/L despite prolonged loading dose (72 h for one-third) and a mean maintenance dose of 300 mg per day. Pharmacokinetics (PK) modeling showed that renal replacement therapy (RRT) was significantly associated with under exposure, explaining a part of clearance variability. The Monte Carlo simulations suggested that the recommended dosing regimen did not achieve the trough target of 2 mg/L in a timely manner (72 h). This is the first isavuconazole PKpop model developed for CAPA critical care patients underlying the need of therapeutic drug monitoring, especially for patients under RRT.
Mitotane is the most effective agent in post-operative treatment of adrenocortical carcinoma. In adults, the starting dose is 2–3 g/day and should be slightly increased to reach the therapeutic index of 14–20 mg/L. This study developed a population PK model for mitotane and to simulate recommended/high dosing regimens. We retrospectively analyzed the data files of 38 patients with 503 plasma concentrations for the pharmacokinetic analysis. Monolix version 2019R1 was used for non-linear mixed-effects modelling. Monte Carlo simulations were performed to evaluate the probability of target attainment (PTA ≥ 14 mg/L) at one month and at three months. Mitotane concentration data were best described by a linear one-compartment model. The estimated PK parameters (between-subject variability) were: 8900 L (90.4%) for central volume of distribution (V) and 70 L·h−1 (29.3%) for clearance (Cl). HDL, Triglyceride (Tg) and a latent covariate were found to influence Cl. The PTA at three months for 3, 6, 9, and 12 g per day was 10%, 55%, 76%, and 85%, respectively. For a loading dose of 15 g/day for one month then 5 g/day, the PTA in the first and third months was 57 and 69%, respectively. This is the first PKpop model of mitotane highlighting the effect of HDL and Tg covariates on the clearance as well as a subpopulation of ultrafast metabolizer. The simulations suggest that recommended dose regimens are not enough to target the therapeutic threshold in the third month.
There is growing evidence of the presence of pharmaceuticals in natural waters and their accumulation in aquatic organisms. While their mode of action on non-target organisms is still not clearly understood, their effects warrant assessment. The present study assessed the metabolome of the Mediterranean mussel (Mytilus galloprovincialis) exposed to a 10 µg/L nominal concentration of the antidepressant venlafaxine (VLF) at 3 time-points (1, 3, and 7 days). Over the exposure period, we observed up- or down-modulations of 113 metabolites, belonging to several metabolisms, e.g., amino acids (phenylalanine, tyrosine, tryptophan, etc.), purine and pyrimidine metabolisms (adenosine, cyclic AMP, thymidine, etc.), and several other metabolites involved in diverse functions. Serotonin showed the same time-course modulation pattern in both male and female mussels, which was consistent with its mode of action in humans, i.e., after a slight decrease on the first day of exposure, its levels increased at day 7 in exposed mussels. We found that the modulation pattern of impacted metabolites was not constant over time and it was gender-specific, as male and female mussels responded differently to VLF exposure.
The use of extended intermittent infusion (EII) or continuous infusion (CI) of meropenem is recommended in intensive care unit (ICU) patients, but few data comparing these two options are available. This retrospective cohort study was conducted between 1 January 2019 and 31 March 2020 in a teaching hospital ICU. It aimed to determine the meropenem plasma concentrations achieved with CI and EII. The study included septic patients treated with meropenem who had one or more meropenem plasma trough (Cmin) or steady-state concentration (Css) measurement(s), as appropriate. It then assessed the factors independently associated with attainment of the target concentration (Cmin or Css ≥ 10 mg/L) and the toxicity threshold (Cmin or Css ≥ 50 mg/L) using logistic regression models. Among the 70 patients analysed, the characteristics of those treated with EII (n = 33) and CI (n = 37) were balanced with the exception of estimates glomerular filtration rate (eGFR): median 30 mL/min/m2 (IQR 30, 84) vs. 79 mL/min/m2 (IQR 30, 124). Of the patients treated with EII, 21 (64%) achieved the target concentration, whereas 31 (97%) of those treated with CI achieved it (P < 0.001). Factors associated with target attainment were: CI (OR 16.28, 95% CI 2.05-407.5), daily dose ≥ 40 mg/kg (OR 12.23, 95% CI 1.76-197.0; P = 0.03) and eGFR (OR 0.98, 95% CI 0.97-0.99; P = 0.02). Attainment of toxicity threshold was associated with daily dose > 70 mg/kg (OR 35.5, 95% CI 5.61-410.3; P < 0.001). The results suggest the use of meropenem CI at 40-70 mg/kg/day, particularly in septic ICU patients with normal or augmented renal clearance.