[Ceftazidime and probabilistic treatment of severe infections in adults]

Probability antibiotic treatments are based on two "best guesses": the nature of the responsible organism and its resistance phenotype. Such treatments are justified in immunocompetent patients with severe infection. The microbiological and pharmacokinetic properties of third generation cephalosporins, and notably ceftazidime, are such that their use as single or combined therapy can be determined. A very wide spectrum and a tendency towards a stronger bactericidal effect are in favour of monotherapy preceded by a short course of bitherapy, especially in cases of hospital-acquired infections.