gms | German Medical Science

Aim: Severe infections in critically ill patients are associated with poor clinical outcomes. They are infected by less suspectible and multiresistent pathogens and show altered and variable antibiotic pharmacokinetics. Underdosing as well as overdosing of drugs may create serious consequences.

Method: Antimicrobial therapy should be individualised on the basis of microbiological as well as pharmacokinetical criteria to ensure effective therapy and to minimise adverse reactions.

Results: Summaries of product characteristics and package leaflets of drugs don’t, or only sparsely, contain data regarding dosage in this specific patient group for example during continuous renal replacement therapies. Textbooks, lists or dosing nomograms for dose adjustment are in common usage. Therapeutic Drug Monitoring (TDM) of antibiotics includes measurement of plasma concentrations of certain drugs and the interpretation of the results to optimize drug therapy in individual patients. Measured plasma levels are gaining in importance when put in the clinical context. Important factors are size, weight, age, renal function, time of blood draw, concomitant medications, type of infection, (assumed) MICs and the clinical presentation of the patient. In anti-infective therapy, TDM of aminoglycosides and Vancomycin has become part of hospital routine. TDM of β-lactams is less widespread but becoming more important, particularly in ICU. It has to be emphasized that TDM is affected by the multidisciplinary cooperation of physicians, nurses, laboratory technicians and pharmacists.

Conclusion: The presented pharmacy-based assay service offers control over the rational use of antibiotics and coordination of the interpretation and application of the measured drug concentrations. Significant variation observed in the PK/PD targets and dose adjustment strategies used support the need for further studies that robustly define PK/PD targets for ICU patients to ensure a greater consistency of practice for dose adjustment strategies for optimising antibiotic dosing.