Comparison of Antimycotic Activity of Originator and Generics of Voriconazole and Anidulafungin against Clinical Isolates of Candida albicans and Candida glabrata.

BACKGROUND: Concerns have been expressed about the interchangeability of innovator and generic antifungals in their activity and chemical stability. MATERIALS/METHODS: The activity of two different antimycotics was tested, each with one originator and two generics. For voriconazole, the originator VFEND® (Pfizer) and the generics (Ratiopharm and Stada) were used for susceptibility testing (21 clinical isolates of Candida albicans (C. albicans); ATCC-90028 C. albicans) in RPMI growth media in compliance with the EUCAST criteria. Likewise, for anidulafungin, the originator ECALTA® (Pfizer) and the generics (Stada and Pharmore) were used for testing (20 clinical isolates of Candida glabrata (C. glabrata); ATCC-22019 Candida parapsilosis (C. parapsilosis)). Time Kill Curves (TKC) with concentrations above and below the respective MIC were performed for one strain for each antifungal. Stability testing of the antimycotics stored at 4 °C and at room temperature over 24 h was done, and samples were subsequently analyzed with HPLC. RESULTS: MIC results showed no significant difference in activity of generic and innovator antimycotic in all settings, which was also confirmed by TKC. Stability testing revealed no differences between originator and generic drugs. CONCLUSIONS: The present study demonstrates the interchangeability of generic and originator antimycotic in-vitro, potentially leading to broader public acceptance for generic antimycotics.

Human tissue distribution of caspofungin.

Tissue concentrations of caspofungin were determined in nine clinically relevant tissues taken during routine autopsy of 20 patients who had died during caspofungin treatment or within 23 days of cessation. The highest levels were achieved in liver, with concentrations ranging from ≤0.50 to 91.5 µg/g (0.60 µg/g 21 days after the last administration), followed by spleen (<0.25-46.3 µg/g), kidney (<0.25-33.6 µg/g) and lung (<0.25-31.0 µg/g). Intermediate concentrations were found in pancreas, skeletal muscle, thyroid and myocardium. The lowest concentrations were found in brain; caspofungin was only detectable in six of 17 samples. Caspofungin concentrations exceeded the minimum inhibitory concentration values of pathogenic Candida spp. in most of the tissue samples taken from patients who had died during treatment, except in brain samples. These findings warrant clinical outcome studies to establish the optimal treatment for deep-seated candidiasis, and support the current recommendations against echinocandins for treatment of fungal meningoencephalitis.

Matcha Green Tea Powder does not Prevent Diet-Induced Arteriosclerosis in New Zealand White Rabbits Due to Impaired Reverse Cholesterol Transport.

INTRODUCTION: Green tea is associated with decreased risk for cardiovascular disease and stroke. Matcha is a special kind of powdered green tea known for its use in the Japanese tea ceremony. Due to its influence on lipoprotein parameters, it has been postulated to exert antiatherogenic effects. This study investigates whether it modulates the high-density lipoprotein (HDL) function and thereby influences the atherogenic process in an animal model with a strong influence on humans' situation. METHODS AND RESULTS: After a pretreatment phase based on a standard diet, 10 female New Zealand White (NZW) rabbits are fed a high-fat diet for 20 weeks. The treatment group is additionally administered 1% matcha during the whole experiment. Long-term matcha treatment leads to lowered HDL cholesterol, impaired cholesterol transport manifested by reduced in vitro cholesterol efflux capacity, reduced cholesteryl ester transfer protein (CETP)-mediated cholesterol ester (CE) transfer between HDL and triglyceride-rich particles, and reduced macrophage-specific in vivo transfer, where ian increased absorption of cholesterol in the liver but a decreased secretion into bile is observed. Pulse wave velocity, assessed by nuclear magnetic resonance, is increased in matcha-treated animals, and a similar trend is observed for atherosclerotic lesion formation. CONCLUSION: Long-term matcha green tea treatment of hypercholesterolemic rabbits cause impaired reverse cholesterol transport and increased vascular stiffness, and susceptibility for atherosclerotic lesion development.

Pharmacokinetics and Antifungal Activity of Echinocandins in Ascites Fluid of Critically Ill Patients.

The pharmacokinetics and antifungal activity of the echinocandins anidulafungin (AFG), micafungin (MFG), and caspofungin (CAS) were assessed in ascites fluid and plasma of critically ill adults treated for suspected or proven invasive candidiasis. Ascites fluid was obtained from ascites drains or during paracentesis. The antifungal activity of the echinocandins in ascites fluid was assessed by incubation of Candida albicans and Candida glabrata at concentrations of 0.03 to 16.00 µg/ml. In addition, ascites fluid samples obtained from our study patients were inoculated with the same isolates and evaluated for fungal growth. These patient samples had to be spiked with echinocandins to restore the original concentrations because echinocandins had been lost during sterile filtration. In ascites fluid specimens of 29 patients, echinocandin concentrations were below the simultaneous plasma levels. Serial sampling in 20 patients revealed a slower rise and decline of echinocandin concentrations in ascites fluid than in plasma. Proliferation of C. albicans in ascites fluid was slower than in culture medium and growth of C. glabrata was lacking, even in the absence of antifungals. In CAS-spiked ascites fluid samples, fungal CFU counts moderately declined, whereas spiking with AFG or MFG had no relevant effect. In ascites fluid of our study patients, echinocandin concentrations achieved by therapeutic doses did not result in a consistent eradication of C. albicans or C. glabrata. Thus, therapeutic doses of AFG, MFG, or CAS may result in ascites fluid concentrations preventing relevant proliferation of C. albicans and C. glabrata, but do not warrant reliable eradication.

Penetration of echinocandins into wound secretion of critically ill patients.

PURPOSE: Wound infections caused by Candida are life-threatening and difficult to treat. Echinocandins are highly effective against Candida species and recommended for treatment of invasive candidiasis. As penetration of echinocandins into wounds is largely unknown, we measured the concentrations of the echinocandins anidulafungin (AFG), micafungin (MFG), and caspofungin (CAS) in wound secretion (WS) and in plasma of critically ill patients. METHODS: We included critically ill adults with an indwelling wound drainage or undergoing vacuum-assisted closure therapy, who were treated with an echinocandin for suspected or proven invasive fungal infection. Concentrations were measured by liquid chromatography with UV (AFG and MFG) or tandem mass spectrometry detection (CAS). RESULTS: Twenty-one patients were enrolled. From eight patients, serial WS samples and simultaneous plasma samples were obtained within a dosage interval. AFG concentrations in WS amounted to < 0.025-2.25 mg/L, MFG concentrations were 0.025-2.53 mg/L, and CAS achieved concentrations of 0.18-4.04 mg/L. Concentrations in WS were significantly lower than the simultaneous plasma concentrations and below the MIC values of some relevant pathogens. CONCLUSION: Echinocandin penetration into WS displays a high inter-individual variability. In WS of some of the patients, concentrations may be sub-therapeutic. However, the relevance of sub-therapeutic concentrations is unknown as no correlation has been established between concentration data and clinical outcome. Nevertheless, in the absence of clinical outcome studies, our data do not support the use of echinocandins at standard doses for the treatment of fungal wound infections, but underline the pivotal role of surgical debridement.

Human Tissue Distribution of Anidulafungin and Micafungin.

Concentrations of anidulafungin and micafungin were determined in eight different tissues obtained during autopsy of four deceased individuals who had been treated with anidulafungin and of seven who had received micafungin. The largest amounts were recovered from liver, with anidulafungin concentrations of 11.01 to 66.50 µg/g and micafungin levels of 0.36 to 5.53 µg/g (0.65 µg/g 30 days after the last administration). The lowest anidulafungin levels were measured in skeletal muscle, and the lowest micafungin concentrations were in kidneys.

Anidulafungin and Micafungin Concentrations in Cerebrospinal Fluid and in Cerebral Cortex.

Anidulafungin and micafungin were quantified in cerebrospinal fluid (CSF) of critically ill adults and in cerebral cortex of deceased patients. In CSF, anidulafungin levels (<0.01 to 0.66 µg/ml) and micafungin levels (<0.01 to 0.16 µg/ml) were lower than those in plasma concentrations (0.77 to 5.07 and 1.21 to 8.70 µg/ml, respectively) drawn simultaneously. In cerebral cortex, anidulafungin and micafungin levels were 0.21 to 2.34 and 0.18 to 2.88 µg/g, respectively. Thus, MIC values of several pathogenic Candida strains exceed concentrations in CSF and in brain.

Pharmacokinetics of trimethoprim/sulfametrole in critically ill patients on continuous renal replacement therapy.

OBJECTIVES: We investigated the effect of continuous renal replacement therapy (CRRT) on the pharmacokinetics of trimethoprim and sulfametrole. PATIENTS AND METHODS: We enrolled critically ill adults undergoing CRRT and critically ill adults with normal or slightly impaired renal function (plasma creatinine concentration <1.5 mg/dL, control group). All patients received trimethoprim/sulfametrole at standard doses. Pharmacokinetics were determined after the first dose and at steady-state. In addition, a population pharmacokinetic model using plasma data was built. We also assessed the renal clearance (CLR) and the extracorporeal clearance in patients undergoing CRRT. RESULTS: Twelve patients were enrolled in the CRRT group and 12 patients in the control group. There was no statistically significant difference in trimethoprim pharmacokinetics between the two groups. In patients on CRRT, total plasma clearance (CLtot) and V of sulfametrole were significantly higher than in the control group. However, sulfametrole exposure was not significantly altered during CRRT. The population pharmacokinetic analysis indicated that neither CRRT intensity nor residual diuresis were significant covariates on trimethoprim or sulfametrole CL. Median CL by continuous venovenous haemofiltration accounted for about one-third of CLtot of trimethoprim and for about one-half of CLtot of sulfametrole. In patients on CRRT, CLR of trimethoprim and sulfametrole were <5% of CLtot. CONCLUSIONS: During CRRT, standard doses of trimethoprim/sulfametrole appear to be adequate.

Quantification of anidulafungin and micafungin in human body fluids by high performance-liquid chromatography with UV-detection.

The echinocandins anidulafungin (ANID) and micafungin (MICA) are recommended for treatment of invasive Candida infections. As target-site concentrations of antimicrobial agents are crucial for eradication of pathogens, we established and validated high-performance liquid chromatography-UV detection (HPLC-UV) assays for quantification of ANID and MICA in human plasma, ascites fluid, pleural effusion, and in cerebrospinal fluid (CSF). Sample pre-purification was performed by protein precipitation with acetonitrile followed by solid phase extraction. For both assays, intra- and interday precision, and accuracy fulfilled the requirements for bioanalytical methods issued by the European Medicine Agency (EMA). The lower limit of quantification was 0.01 mg/L for both drugs. At 25 °C, ANID and MICA concentrations declined by up to 70% within 24 h. Concentrations remained stable over 24 h at 4 °C and over four weeks at -80 °C. In conclusion, the developed methods are fit for the assessment of target-site pharmacokinetics of ANID and MICA in clinical studies.

Biliary amphotericin B pharmacokinetics and pharmacodynamics in critically ill liver transplant recipients receiving treatment with amphotericin B lipid formulations.

Fungal cholangitis is a potentially life-threatening condition. As amphotericin B (AmB) has a broad antimycotic spectrum, in this study its biliary penetration and activity was determined in two patients treated with liposomal AmB (L-AmB) and in one patient receiving AmB colloidal dispersion (ABCD). Biliary and plasma AmB levels were quantified by high-performance liquid chromatography after purification by solid-phase extraction. For assessment of biliary AmB activity, isolates of Candida albicans, Candida tropicalis, Candida glabrata and Candida krusei were incubated in porcine bile at AmB concentrations of 0.025-5.00 mg/L. In addition, patient bile samples retrieved for AmB quantification were inoculated with the same Candida strains. Biliary AmB concentrations were lower and displayed a slower rise and decline than plasma levels. The highest penetration ratio, as expressed by the ratio between the area under the AmB concentration-time curve in bile and plasma (liberated AmB) over the sampling period (AUC0-n bile/AUC0-n LI plasma), was 0.28. Proliferation of C. albicans and C. tropicalis in bile was similar to that in culture medium, whereas growth of C. glabrata was diminished and proliferation of C. krusei was absent in bile. In comparison with culture medium, AmB activity decreased in spiked porcine bile. In all but one patient bile sample, fungal growth was delayed or lacking even when AmB was not detectable. However, no fungicidal effect was observed in patient bile at AmB concentrations up to 1.28 mg/L. Thus, a reliable response of fungal cholangitis to treatment with L-AmB or ABCD cannot be anticipated.

Pharmacokinetics of caspofungin in critically ill patients on continuous renal replacement therapy.

Caspofungin pharmacokinetics was assessed in 27 critically ill patients, including 7 on continuous venovenous hemofiltration (CVVH), 8 on continuous venovenous hemodialysis (CVVHD), and 13 not requiring continuous renal replacement therapy (CRRT). Caspofungin exposure during CRRT was very similar to that of the control group and comparable to that in healthy volunteers. Caspofungin clearance by CRRT was very low. Therefore, the standard dosage of caspofungin is probably adequate for critically ill patients undergoing CVVH or CVVHD.