title: Antibiotic therapy for severe bacterial infections: correlation between the inhibitory quotient and outcome.
abstract: In severe bacterial infections, treatment failure can occur even when the infecting organism has displayed in vitro susceptibility to the antibiotics used. Several pharmacokinetic-pharmacodynamic parameters show better correlation with therapeutic outcome than susceptibility results. This study was devised to assess the relation between the inhibitory quotient (IQ), i.e., the ratio of achievable antibiotic concentration at the infection site to the minimum inhibitory concentration for the infecting organism, and both clinical and bacteriological outcomes in 290 severe bacterial infections. Multivariate analysis showed that the IQ was a strong predictor of therapeutic outcome ( P< 0.001-0.002): values <4 predicted failure, and those >or=6 cure. This simple parameter could be routinely used to guide effective antibiotic therapy.
authors.affiliation: Department of Microbiology, Catholic University of the Sacred Heart, Largo F Vito 1, 00168 Rome, Italy. tspanu@rm.unicatt.it
authors.forename: Teresa
authors.initials: T
authors.lastname: Spanu
authors.forename: Rosaria
authors.initials: R
authors.lastname: Santangelo
authors.forename: Felicita
authors.initials: F
authors.lastname: Andreotti
authors.forename: Giuliana Lo
authors.initials: GL
authors.lastname: Cascio
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Velardi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Fadda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000494:pharmacology* / Q000627:therapeutic use; D001419:Bacteria / Q000187:drug effects*; D001424:Bacterial Infections / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents