Application of PK/PD Modeling in Veterinary Field: Dose Optimization and Drug Resistance Prediction

Table 2

Definition of important PK, PD, and PK/PD indices.

PK/PD index	Definition	Unit	References
Pharmacodynamics
MIC	The minimal inhibitory concentration is defined as the lowest concentration of antibiotic that inhibits completely the growth of the specific organism being tested.	mg/L or µg/mL	Mouton et al., 2005 [34]
MBC	MBC is the lowest concentration at which 99.9% reduction in bacterial count is achieved	mg/L or µg/mL	Tayler et al., 1983 [44]
MPC	MPC (mutant prevention concentration): the lowest concentration that prevents the emergence of mutants after 120 hours of incubation	mg/L or µg/mL	Shimizu et al., 2013 [45]
PAE	Postantibiotic effect is the time of suppression of bacterial growth after the bacteria are exposed to antibacterial for a short time	Time (h)	Mouton et al., 2005 [34]
Pharmacokinetics
AUC	The area under the concentration time curve over 24 h at steady state unless otherwise stated. It is equivalent to a single dose AUC0-∞	µg⋅h/mL	Mouton et al., 2005 [34]
	Prefix indicating that the pharmacokinetic parameter values or PK/PD index values used are unbound (free) fractions of the drug
	The highest concentration of drug reached or estimated in the compartment of reference	mg/L or µg/mL	Mouton et al., 2005 [34]
PK/PD integration
> MIC	The cumulative percentage of 24 h period in which the drug concentration exceeds the MIC at steady state pharmacokinetic condition	%	Mouton et al., 2005 [34]
AUC/MIC	The area under the concentration time curve divided by MIC	No unit	Mouton et al., 2005 [34]
/MIC	The peak concentration of drug divided by MIC	No unit	Mouton et al., 2005 [34]