[Antibiotic therapy: from pharmacology to decision making].

The decision of an antibiotic treatment depends first on clinical and bacteriological data. Then PK/PD (pharmacodynamics/pharmacokinetics) of antibiotics must be taken into account in order to optimise the dosing regimen, and to reach the targeted serum concentrations. The good oral bioavailability of some drugs allows the use of the oral route, at the beginning of the treatment, or shortly after an initial successful i.v. administration, even in severe infections.