Aminoglycosides minimum inhibitory concentrations

The maximum plasma concentration reflects the extent of drug bioavailability. It can be used in relation to minimum inhibitory concentration (MIC) to predict the efficacy of concentration-dependent antimicrobial agents (e.g. fluoroquinolones, aminoglycosides). Both the maximum (peak) and minimum (trough) plasma concentrations are used during therapeutic drug monitoring to maximize efficacy and minimize the occurrence of undesirable effects. 

The clinical effectiveness of aminoglycosides and fluoroquinolones is influenced both by the height of the peak plasma concentration relative to the minimum inhibitory concentration (Cmax MIC ratio) and the area under the plasma concentration-time curve that is above the MIC during the dosage interval (AUIC = AUC/MIC). The former is relatively more important for fluoroquinolones maximum activity is achieved when Cmax is in the range 5-10 times the MIC. 

MECHANISM OF ACTION The aminoglycoside antibiotics are rapidly bactericidal. Bacterial killing is concentration-dependent, but residual bactericidal activity persists even after the serum concentration has fallen below the minimum inhibitory concentration. These properties account for the efficacy of once-daily dosing regimens. 

Fig. 11. Various neamine dimers and their respective activities with aminoglycoside deactivating enzymes. The numbers for each strain represent minimum inhibitory concentrations. Reprinted with permission. Copyright 2004 Wiley-VCH Verlag GmbH Co. KgaA.

Table II. Minimum Inhibitory Concentration of the Synthesized Aminoglycoside ...

Table V. Minimum inhibitory concentrations of the Synthesized Aminoglycosides ...

Moore RD, Lietman PS, Smith CR. Clinical response to aminoglycoside therapy importance of the ratio of peak concentration to minimum inhibitory concentration. J Infect Dis 1987 155 93-97. 

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