Effect of paclitaxel alone or in combination on the intracellular penetration and activity of quinolones in human neutrophils

We evaluated the effect of paclitaxel alone or in combination with cisplatin or doxorubicin, on the intracellular penetration and activity of ciprofloxacin, ofloxacin, levofloxacin and sparfloxacin in human polymorphonuclear leukocytes (PMN). In general, paclitaxel either alone or in combination did not affect the intracellular concentrations of the quinolones evaluated (intracellular to extracellular concentration ratio (C/E > 4). However, at high concentrations (20 mg/L) paclitaxel decreased the penetration of ofloxacin and levofloxacin although the C/E ratios remained higher than 3. Paclitaxel alone or in combination affected neither the production of oxygen radicals by PMN nor the intracellular activity of the quinolones against Staphylococcus aureus.