Post-antibiotic effect (PAE) is the time it takes for an organism to show a 1-log increment of growth after being exposed to a drug, and after removal of the drug. Swedish researchers (18) have demonstrated a post-antibiotic sub-minimal effect (PASME) because the complete removal of drug in PAE experiments does not mimic the physiological situation, and PASME markedly prolongs the time taken for the organism to return to log growth relative to PAE (19). It has also been shown that drug exposure enhances post-antibiotic leukocyte effect (PALE) (20), indicating that drug exposure allows white cells to kill better. All of these terms are now thought of as integrated into the single term persistent effect, and probably explains why fluoroquinolones have AUC/MIC ratio as their dynamically linked variable in most instances.