Rationality Appraisal Of Linezolid Injection In Clinical Application And Determination Of Linezolid In Critical Ill Patients Plasma

Infections caused by susceptible gram-positive effect patients，according tostatistics, over the past ten years, drug-resistant bacteria species grew20timesworld-wide[1]. Present study shows that Infections caused by methicillin-resistantstaphylococcus aureus (MRSA) is difficult to treat[2], systemic infection with highmortality, it is a important bacterias of hospital infection. The oxazolidinone linezolidis one of only a few new agents approved in recent times for the treatment of infectionscaused by multidrug-resistant gram-positive bacteria. It against Methicillin-resistantStaphylococcus aureus(MRSA)、 Vancomycin-resistant Enterococcus(VRE)、Hetero-resistane vancomycin-inter-mediate S aureus(hVISA)、Vancomycin-intermediaS aureus(VISA).It is chemically unrelated to currently available agents and inhibitsbacterial protein synthesis[3].OBJECTIVE: To investigate the clinical application of linezolid injection a3-A gradehospital from2009~2010to evaluate its rationality of use and establish an HPLCmethod to determine the concentration of linezolid in human plasma, and use themethod in critically ill patients,in order to provide reference for clinical application.METHOD: We selected the patients treated with linezolid injection in a3-A gradehospital from2009-2010.Themedicines directions and relevant guidelines for diagnosisand treatment of antibacterial were used for reference to evaluate the rationalityincluding clinical efficacy and safety of linezolid injection application. To establish anHPLC method to determine the concentration of linezolid in human plasma, and usethe method in critically ill patients. RESULTS: Of the163patients，the age group less than11year accounted for10（6.13%）of total inpatients，the age old than12years for153（93.87%）；The rationaland reasonable in use basically accounted for65.03%，unreasonable for34.97%；112（68.71%）patients were cured,25（15.34%）were effected，9（5.52%）were improved，17（10.43%） were invalid.. Use linezolid injection to treat infection25(15.34%),combine with one drug was86(52.76%), two32(19.63%), three16(9.82%), four4(2.45%).18（11.04%）patients were found with thrombocytopenia afterusing linezolid injection.To establish an HPLC method, A Shim pack ODS (250×4.6mm，5μm) columwas used. The mobile phase consisited of0.2%phosphoric acid solution (A) andacetonitrile (B) with isocratic elution. The column temperature was40℃, and the flowrate was1.0mL·min-1. The detection wavelength was set at254nm. With inconcentration0.10~41.20mg·L-1is relative standard(r=0.9998); lod0.05mg·L-1;intra-and inter-day precision＜4.3％。Six patients with critical ill, after diagnosis andtreat in hospital, use linezolid injection600mg, after30min, collect blood withlinezolid concentration maxmum and concentration minimum. It is difference betweensix patients’ concentration maxmum and concentration minimum. There are one patientwith linezolid trough concentrations less than the mini mum inhibitory concentrations.CONCLUSION: There is some irrational clinical application of linezolid injection inthe3-A grade hospital, and which indicate that there is space for standardized linezolidinjection application to develop. Research shows that it has high rate of adverse effecton platelet, which should be confirmed in future practice. The method is simple,sensitive, accurate and suitable for the determination of linezolid in critical ill patientsplasma and clinical pharmacokinetic studies.