Comparison between two different administration methods (continuous or intermittent) of Tazocilline, a time-dependent antibiotic.

A predictive parameter of beta -lactamines therapeutic efficacy is the time (T > MIC) while antibiotic seric concentrations are above the MIC of suspe cted bacteriological agents. This led us to carry out a randomised open stu dy to compare the usually used intermittent administration of Tazocilline ( three injections of 4 g/0.5 g a day) and continuous perfusion of 12 g/1.5 g a day by calculating these T > MIC. Patients from digestive reanimation de partment were randomised within two arms: continuous or Intermittent admini stration. Sixteen taking of blood were executed over a forty hour period. A fter liquid/liquid extraction, piperacillin and tazobactam seric concentrat ions were determined by HPLC with a reversed phase column (C18) and a UV sp ectrophotometry detection. Then, from the time-concentration curves we have evaluate the T > MIC for an enterobacteria (MIC = 8 mug/mL) and for Pseudo monas (MIC = 16 mug/mL). Concerning intermittent administration T > MIC wer e 74% (c > MiC(enterobacteria)) and 62% (c > MICPseudomonas). These percent ages in the continuous arm were 100% (c > MiC(enterobacteria)) and 99% (c > MICPseudomonas). Tazobactam concentrations were low and even undetectable between each injection in the intermittent administration arm. This were no t find within the continuous administration arm. In conclusion, for the int ermittent administration, we observed some long periods occurring before ea ch injection white antibiotic concentrations were under the MIC of most bac teria. During these same periods tazobactam concentrations were under the e fficacy threshold. These periods were not observed within the continuous ad ministration arm. (C) 2001 Editions scientifiques et medicales Elsevier SAS .