[Multiresistant pathogens--a challenge for clinicians].

Gram-negative pathogens are currently isolated frequently in invasive nosocomial infections and give rise to major therapeutic problems due to their resistance pattern. Metaanalyses of randomised controlled studies have demonstrated that an antibiotic combination treatment is not indicated in many cases. However, in critically ill patients (septic shock) and also in immunocompromised patients with previous intensive care as well as broad spectrum antibiotic treatment, a combination of antibiotics is recommended. This therapy should be based on the source of the infection, on local resistance data, on antibiotic pretreatment, on basic diseases of the patient and on current liver and renal functions. The start of therapy should be as fast as possible after collection of optimal materials for microbiological analysis. Dosage of selected antibiotics should be based on rational pharmacokinetic and pharmacodynamic parameters. A de-escalation of antibiotics is strongly recommended in all international guidelines based on the microbiological results and the clinical response of the patient. New antibiotics or therapeutic strategies against multiresistant Gram-negative pathogens will not be available in the next 5 to 10 years; therefore, it is absolute mandatory to use the currently still effective antibiotics, like carbapenems and polymyxins, very rationally and restrictively. Georg Thieme Verlag KG Stuttgart · New York.