Assessment of immunomodulating activity of ofloxacin and three other quinolones in human plasma.

A time-dependent degree of immunosuppression or immunostimulation which may be correlated to pharmacokinetic variables was obtained by administering a single dose of ofloxacin, norfloxacin, pipemidic and piromidic acid to healthy volunteers. The plasma samples collected before drug administration and then at various time intervals were tested for their immunomodifying activity by employing a modified 2-way mixed lymphocyte reaction and a PMN chemotactic assay. Our results show that some of the quinolones tested--norfloxacin, pipemidic acid, piromidic acid--have an immunosuppressive activity.