Antibiotic therapy for severe bacterial infections: correlation between the inhibitory quotient and outcome.
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.
Spanu
Teresa
T
Department of Microbiology, Catholic University of the Sacred Heart, Largo F Vito 1, 00168 Rome, Italy. tspanu@rm.unicatt.it
Santangelo
Rosaria
R
Andreotti
Felicita
F
Cascio
Giuliana Lo
GL
Velardi
Giuseppe
G
Fadda
Giovanni
G
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
D000900:Anti-Bacterial Agents