Evaluation of Pharmacokinetic / Pharmacodynamic Data and Interest Individualized Therapeutic Drug Monitoring Glycopeptides and β-lactam-aminoglycoside ICU

Since the discovery of streptomycin in 1944, aminoglycosides retain a remarkable bactericidal activity vis-à-vis including aerobic gram-negative bacilli. Thus, their synergistic effect with beta-lactams and their rapid bactericidal on many make unavoidable pathogens and make it a cornerstone of the treatment of patients with severe sepsis or state of septic shock.

This is antibiotics exclusively parenteral administration. Their effectiveness is concentration-dependent and are administered by 30-minute infusion. Tolerance of venous is usually excellent. Their potential nephrotoxicity or cochleovestibular toxicity requires accurate monitoring of antibiotic residuals.

Moreover the fact that the effectiveness of the aminoglycosides is concentration dependent, the rate at the peak is decisive. A first sub-therapeutic dose leads to adaptively resistant bacteria compared to the aminoglycoside and therefore an increase of Minimal Inhibitory Concentrations (MIC). Many studies have been conducted in patients hospitalized in intensive care, highlighting underdoses in aminoglycosides when the prescribed dosages consistent with those used in non reanimated patients. Dr Moore showed in 89 ICU patients with bacteremia gram-negative bacilli, the relationship between the clinical course and obtaining whether therapeutic levels during the first administration of aminoglycosides. Thus, mortality in patients whose antibiotic concentrations to peak were subtherapeutic, amounted to 20.9% against 2.4% when concentrations were within the therapeutic range. In the context or an initial peak in the PK / PD ( Pharmacokinetic / Pharmacodynamic) objectives namely Cmax / MIC ≥ 8-10 desirable, individualized therapeutic drug monitoring and identification of factors that may cause a concentration of antibiotic at sub-therapeutic peak seems necessary , in patients for the majority an increased volume of distribution.

In addition to the β-lactams and glycopeptides, due to the increased volume of distribution in critically ill patients in sepsis, evaluation of serum 24 hours after starting treatment to check that the PK / PD goals for these molecules is achieved.