Isavuconazole Therapeutic Drug Monitoring in critically ill ICU patients - a monocentric retrospective analysis

BACKGROUND

The broad-spectrum triazole isavuconazole is used for the treatment of invasive aspergillosis and mucormycosis. Data regarding human plasma concentrations in clinical routine of the drug are rare.

OBJECTIVES

Plasma concentrations of isavuconazole were determined in critically ill ICU patients while considering different patients' characteristics.

METHODS

Retrospective analysis of isavuconazole plasma concentrations were obtained as part of routine therapeutic drug monitoring (TDM) of ICU patients with invasive aspergillosis or other fungal infections treated with isavuconazole. Plasma levels 0-4h after last dosing were defined as peak levels (C_max ), those 20-28h after last dosing as trough levels (C_min ).

RESULTS

Overall, 223 isavuconazole levels of 41 patients were analysed, divided into 141 peak levels and 82 trough levels. The overall median C_max was 2.36 μg/mL (mean 2.43 μg/mL, range 0.41 - 7.79 μg/mL) and the overall median C_min was 1.74 μg/mL (mean 1.77 μg/mL, range 0.24 - 4.96 μg/mL). In total, 31.7% of the C_min values of the total cohort were below the plasma target concentrations of 1 μg/mL, defined as EUCAST antifungal clinical breakpoint for Aspergillus fumigatus. Both peak and trough plasma levels of isavuconazole were significantly lower among patients with a body-mass-index (BMI) ≥ 25. In addition, a significant correlation was observed between isavuconazole trough levels and sepsis-related organ failure assessment (SOFA) score.

CONCLUSIONS

This study shows that isavuconazole plasma concentrations vary in critical ill ICU patients. Significantly lower isavuconazole levels were associated with elevated BMI and higher SOFA score indicating a need of isavuconazole TDM in this specific patient population.

Affinity Series of Genetically Encoded Förster Resonance Energy-Transfer Sensors for Sucrose

Genetically encoded fluorescent sugar sensors are valuable tools for the discovery of transporters and for quantitative monitoring of sugar steady-state levels in intact tissues. Genetically encoded Förster resonance energy-transfer sensors for glucose have been designed and optimized extensively, and a full series of affinity mutants is available for in vivo studies. However, to date, only a single improved sucrose sensor FLIPsuc-90μΔ1 with K_m for sucrose of ∼90 μM was available. This sucrose sensor was engineered on the basis of an Agrobacterium tumefaciens sugar-binding protein. Here, we took a two-step approach to first improve the dynamic range of the FLIPsuc sensor and then expand the detection range from micro- to millimolar sucrose concentrations by mutating a key residue in the binding site. The resulting series of sucrose sensors may enable investigation of sucrose transporter candidates and comprehensive in vivo analyses of sucrose concentration in plants. Since FLIPsuc-90μ also detects trehalose in animal cells, the new series of sensors will likely be suitable for investigating trehalose transport and monitor trehalose steady-state levels in vivo.

Emulsions with unique properties from proteins as emulsifiers

Many proteins are surface active molecules and form stable emulsions. In these emulsions, the protein covered oil droplets behave as sticky droplets even when they are ionically charged. As a result of the stickiness of the droplets the emulsions have gel-like properties. The stickiness is due to the multipolar nature of the proteins in contrast to the bipolar nature of surfactants or other amphiphilic compounds that form emulsions with repulsive droplets. Stable emulsions are also formed from particles like clays to which proteins are adsorbed. These hybrid compounds form even more stable emulsions with stronger elastic properties than clays and proteins on their own. These so called pickering emulsions have paste-like properties and do not flow. The scaffolding network of the crosslinked protein bilayers on the droplets is so strong that both the water and the oil can be removed from the emulsions by freeze drying without collapse of the scaffold. The resulting sponge can be used again for the uptake of both water and oil. Emulsions which are prepared from different proteins differ mainly in their elastic properties.

Exercise efficiency of low power output cycling

Exercise efficiency at low power outputs, energetically comparable to daily living activities, can be influenced by homeostatic perturbations (e.g., weight gain/loss). However, an appropriate efficiency calculation for low power outputs used in these studies has not been determined. Fifteen active subjects (seven females, eight males) performed 14, 5-min cycling trials: two types of seated rest (cranks vertical and horizontal), passive (motor-driven) cycling, no-chain cycling, no-load cycling, cycling at low (10, 20, 30, 40 W), and moderate (50, 60, 80, 100, 120 W) power outputs. Mean delta efficiency was 57% for low power outputs compared to 41.3% for moderate power outputs. Means for gross (3.6%) and net (5.7%) efficiencies were low at the lowest power output. At low power outputs, delta and work efficiency values exceeded theoretical values. In conclusion, at low power outputs, none of the common exercise efficiency calculations gave values comparable to theoretical muscle efficiency. However, gross efficiency and the slope and intercept of the metabolic power vs mechanical power output regression provide insights that are still valuable when studying homeostatic perturbations.

Repeat traumatic brain injury in the juvenile rat is associated with increased axonal injury and cognitive impairments

Among the enormous population of head-injured children and young adults are a growing subpopulation who experience repeat traumatic brain injury (RTBI). The most common cause of RTBI in this age group is sports-related concussions, and athletes who have experienced a head injury are at greater risk for subsequent TBI, with consequent long-term cognitive dysfunction. While several animal models have been proposed to study RTBI, they have been shown to either produce injuries too severe, were conducted in adults, involved craniotomy, or failed to show behavioral deficits. A closed head injury model for postnatal day 35 rats was established, and single and repeat TBI (1-day interval) were examined histologically for axonal injury and behaviorally by the novel object recognition (NOR) task. The results from the current study demonstrate that an experimental closed head injury in the rodent with low mortality rates and absence of gross pathology can produce measurable cognitive deficits in a juvenile age group. The introduction of a second injury 24 h after the first impact resulted in increased axonal injury, astrocytic reactivity and increased memory impairment in the NOR task. The histological evidence demonstrates the potential usefulness of this RTBI model for studying the impact and time course of RTBI as it relates to the pediatric and young adult population. This study marks the first critical step in experimentally addressing the consequences of concussions and the cumulative effects of RTBI in the developing brain.

Adjunctive therapies in the cath lab. Use of combination glycoprotein IIb/IIIa inhibitor and direct thrombin inhibitor drugs to support percutaneous coronary stent placement in a patient with renal insufficiency and heparin-induced thrombocytopenia

An 81-year-old woman with a history of prior coronary artery bypass surgery, heparin-induced thrombocytopenia with "white clot" syndrome, and renal insufficiency presented with unstable angina. She was referred for cardiac catheterization. Complex percutaneous revascularization of the native circumflex coronary artery was performed using stents. A combination of tirofiban and lepirudin was used with dosing adjusted for renal insufficiency. The hospital course was uncomplicated and the patient was discharged on the fourth hospital day. This is only the second report of the combination use of direct thrombin inhibitor and glycoprotein IIb/IIIa receptor inhibitor.

An unusual complication during deployment of a Multi-Link stent

The use of intracoronary stents has greatly impacted on the practice of interventional cardiology. Complications due to equipment failure during deployment of stents are rare but potentially serious. We report a case of a malfunctioning Multi-Link delivery system and the successful treatment of the resulting complications.

Acute renal failure following low osmolality radiocontrast dye

It is hoped that recently released low osmolality radiocontrast agents (RCAs) will have a lower nephrotoxic potential, since dye nephropathy may be related to hyperosmolality. We report here 2 cases of typical oliguric dye nephropathy in patients without risk factors for dye nephropathy. These cases show that these new agents do have nephrotoxic potential.

Electrocardiographic criteria for the diagnosis of anterior myocardial infarction: importance of the duration of precordial R waves

A systematic evaluation of a large number of electrocardiographic (ECG) variables that might be useful for diagnosing anterior myocardial infarction (MI) is reported. Previous anterior MI was shown to be present or absent by cardiac catheterization in 199 patients. The best discriminator between cases and noncases of anterior MI in most patients is the presence of a Q wave of any magnitude or an initial R wave less than 20 ms in lead V2. In patients with ECG evidence of associated left ventricular or type C right ventricular enlargement, the more stringent criterion of a Q wave of any magnitude in lead V2 yielded the optimal combination of sensitivity and specificity for diagnosing anterior MI. The diagnostic performance of the proposed criteria for anterior MI is superior to that of more traditional criteria that use measurements of the absolute and relative amplitudes of precordial R waves.