Det er dog allerede kendt, at andengenerations- fluoroquinoloner (ciprofloxacin, ofloxacin og levofloxacin) giver højere serumkoncentrationer og en mere fordelagtig vævsfordeling end norfloxacin.
It is though known that the second generation fluoroquinolones (ciprofloxacin, ofloxacin and levofloxacin) show higher serum concentrations and a more favourable tissue distribution than norfloxacin.