Antibiothérapie des infections urinaires basses: bases cliniques, microbiologiques et pharmacologiques

While uncomplicated lower urinary tract infection (UTI) in young women is a common and very frequent disorder, change and progress in the infection's management, choice of antimicrobial agents and whether or not it is necessary to perform urine cultures and antibiotic susceptibility testing, are not precluded. Among the factors supporting use of urine cultures, the increasing emergence of antibiotic-resistant bacteria may theoretically pose an argument for use of this test. And yet, epidemiological studies on urinary tract infections have investigated the predominant uropathogens and their antibiotic sensitivity: the results for several years of data show the stable incidence of Escherichia coli, Proteus mirabilis, Klebsiella spp or Staphylococcus saprophyticus; the investigations' results also demonstrate low resistance rates to the most frequently used antimicrobial agents, with the exception of beta-lactams, represented mainly by aminopenicillins. The availability of several new classes of antibiotics and the development of antibiomicrobial agents specific to urinary infections are factors allowing empirical treatment of uncomplicated lower UTIs. In this case, the use of urine culture to diagnose urinary tract infections is called into question, the clinical presentation and use of urine dip-sticks being adequate. Finally, the change in therapeutic strategy towards shorter treatment regimens with an optimum 3-day course of therapy, is manifested by treatment with fluoroquinolones, which are broad-spectrum antimicrobial agents that are mainly excreted in the urine. This latter pharmacokinetic parameter makes it possible to ensure bacterial eradication when high doses (cause of poor safety profile) of the selected compound are not necessary, when this compound is weakly bound to plasma proteins, undergoes little metabolism and maintains high urinary concentrations of the product in unchanged form that persist after the end of treatment.