PK/PD and point mutations ...
The "Mutant Prevention Concentration" *
"When Mycobacterium bovis BCG and Staphylococcus aureus were plated on agar containing increasing concentrations of fluoroquinolone, colony numbers exhibited a sharp drop, followed by a plateau and a second sharp drop.
The plateau region correlated,vith the presence of first-step resistant mutants. Mutants were not recovered at concentrations above those required for the second sharp drop, thereby defining a mutant prevention concentration (MPC).
A C8-methoxy group lowered the MPC for N-1-cyclopropylfluoroquinolones