Invited Paper

Importance of Pharmacokinetic/Pharmacodynamic Concept in Antibiotic Therapy


  • Tuğba Gümüștaș
  • Nihan Küçük
  • Mehmet Melli

Received Date: 03.03.2018 Accepted Date: 16.10.2017 J Ankara Univ Fac Med 2018;71(1):23-29

Inappropriate dosing of antibiotics used in the treatment of infectious diseases leads to the emergence of bacterial resistance which in turn, gives rise to the development of new infections with these resistant bacte- ria. This issue constitutes the major problem in the treatment of infectious diseases. The recognition and the co-evaluation of the principles of pharmacodynamics (PD) and pharmacokinetics (PK) determining the treatment response to antimicrobial therapy provides the proper arrangement of the dosing regimens used in the treatment. The three widespreadly used PD/PK parameters for the prediction of antibiotic efficacy are; (1)the ratio of maximum serum concentration (Cmax) to minimum inhibitory conncentration(MIC) (Cmax/MIC), (2) the ratio of the area under the plasma concentration versus time curve (AUC) to MIC (AUC/MIC), and (3) the duration of the dosing interval that plasma concentrations exceed the MIC value (T>MIC). According to PD/PK approach, antibiotics are classified as; 1) concentration-dependent (aminoglycosides, flu- oroquinolones, etc.), and 2) time-dependent (beta-lactams, glycopeptides, etc.). It is demonstrated that the antibiotics in the first group act better when the daily dose is given at a single dose, whereas the antibiotics in the second group act better when the daily dose is given in divided doses. The determination of dosing regimens by the way of PD/PK approach instead of the MIC value only, has been considered recently in the treatment modalities since it enables successful eradication of bacteria, reduces toxicity, alleviates the likelihood of the generation of resistant strains and consequently increases the clinical success rate. In this review, clinical implications of antibiotic use according to PK/PD principles in the treat- ment of infectious diseases have been discussed.

Keywords: Antibiotics, PK/PD, T>MIC, Cmax/MIC, AUC/MIC