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Polymyxin B, which is a last-line antibiotic for extensively drug-resistant Gram-negative bacterial infections, became available in China in Dec. 2017. As dose adjustments are based solely on clinical experience of risk toxicity, treatment failure, and emergence of resistance, there is an urgent clinical need to perform therapeutic drug monitoring (TDM) to optimize the use of polymyxin B. It is thus necessary to standardize operating procedures to ensure the accuracy of TDM and provide evidence for their rational use. We report a consensus on TDM guidelines for polymyxin B, as endorsed by the Infection and Chemotherapy Committee of the Shanghai Medical Association and the Therapeutic Drug Monitoring Committee of the Chinese Pharmacological Society. The consensus panel was composed of clinicians, pharmacists, and microbiologists from different provinces in China and Australia who made recommendations regarding target concentrations, sample collection, reporting, and explanation of TDM results. The guidelines provide the first-ever consensus on conducting TDM of polymyxin B, and are intended to guide optimal clinical use.
Assuntos
Humanos , Antibacterianos/uso terapêutico , China , Monitoramento de Medicamentos/métodos , Polimixina B , Guias de Prática Clínica como AssuntoRESUMO
Objective To construct a new intubation method with an otoscope and establish a murine model of Acinetobacter baumannii pneumonia with this method.Methods Part I:The Hallowell Intubation Pack for mice (Braintree Scientific Inc., USA)was used to construct a new intubation method with an otoscope.Part II:Twenty-four female ICR mice were randomized into 3 groups including control (group 1),immunosuppression (group 2)and infection after immunosuppression groups (group 3),with 8 mice in each group.The mice were treated with cyclophosphamide (CTX)by peritoneal injection to posterior orbital venous plexus.The total number of white blood cells,the number of neutrophils and the percentage of neutrophils were determined.Four mice were sacrificed at 0 h and 48 h after inoculation in each group.Then the lungs from each mouse were aseptically collected for quantitative culture and histopathology.Results Part I:Ten mice were successfully intubated using the new method and none of the mice was dead.Pulmonary bacterial culture at baseline (0 h)was (2.91×107-5.32×107 )CFU/g tissue,while the mean± standard deviation was (4.05 × 107 ± 0.82 × 107 )CFU/g tissue.The results showed that this new method had a perfect repeatability.Part II:Over 48 h,2 mice were dead in group 3,while no mouse was dead in other 2 groups.For group 3,the average pulmonary bacterial culture was 4.13×107 CFU/g tissue at 0 h and reached 3.62×1010 CFU/g tissue at 48 h (increased appropriate 1 000 times,P <0.01).The histopathologic changes in lung showed local granulomas and abscess in the alveolar space.Conclusions Intubation under the guidance of otoscope had the advantages of high repeatability and easy to operate.Additionally,the method provided stable and consistent bacterial inocula into lungs.The murine model of Acinetobacter baumannii pneumonia was successfully established with a new intubation method under the guidance of otoscope.
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Objective To establish and validate an ultra performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS)method for quantification of MRX-I,a new oxazolidinone antibacterial agent,in human plasma and urine.Methods Chromatographic separation was performed on a Waters ACQUITY UPLC BEH C8 column using an isocratic elution.The mo-bile phase consisted of acetonitrile and water (40∶60,v/v).Quantitative analysis was conducted in the multiple reaction moni-toring mode.Linezolid was used as an internal standard.Liquid-liquid extraction with ethyl acetate was used to remove impuri-ties in the plasma and urine samples.The method was validated in terms of matrix effect,recovery,precision,accuracy and stability.Results The calibration curves were linear within the range of 0.005 00-1 .00 mg/L.The lower limit of quantification was 0.005 00 mg/L for both plasma and urine samples.Retention time was less than 1 .5 min for both MRX-I and internal standard in plasma and urine.The ma-trix effect factors of plasma and urine for MRX-I was 90.4%±8.2% and 82.7%±7.9%,respectively.The recovery of MRX-I was 112.8% ± 13.4% from plasma and 105.6% ± 13.4% from urine samples,respectively.The inter- and intra-day accuracy of MRX-I was 98.9%-105.0% and 96.5%-102.6% in plasma samples,and 92.7%-98.6% and 95.1 %-105.7% in urine samples.MRX-I was stable for 24 h at room tem-perature,48 h in automatic sampler after pretreatment,and stable after 3 freeze-thaw cycles in plasma and urine.MRX-I was also stable at-40℃for eight months in plasma and six months in urine,respectively.Conclusions The UPLC-MS/MS method established in this study shows high sensitivity and specificity for determination of MRX-I in human plasma and urine.The re-sults of validation are consistent with the requirement of bioanalytical method validation.