Fluoroquinolone’s (FQs) pharmacological properties, patient
characteristics, and microorganisms responsible for infection play a key
role in clinical outcomes. FQs are prescribed in systemic infections due
to the adequate disposition properties of the antibiotic at the site of
infection. However, variability in important interindividual
pharmacokinetic aspects, especially in the elimination process, may
contribute to treatment failure. Likewise, today, undesired
interregional variability in FQs antimicrobial activity against certain
microorganisms exists. The aim of this study was to review the published
information about interindividual variability in pharmacological
processes for the most used FQs, such as ciprofloxacin, levofloxacin,
and moxifloxacin. This review was deemed necessary on the basis of
understudied interindividual pharmacokinetic and pharmacodynamic
variability of FQs. The understanding of FQs dose-response relationship
is critical to optimize the effectiveness of FQs therapy used to treat
systemic infections. This may be particularly critical in the case of
special populations such as critical ill, elderly, renal, and obese
patients. The altered PK in these patients associated with creatinine
clearance, together with the variability in pathogen susceptibility,
associated with local resistances, may require personalized dosing
regimens. Patient-tailored effective FQs dosing is needed to guarantee
antimicrobial efficacy while minimizing the risk of adverse events and
emergence of resistance.