EFFECTS OF LOMEFLOXACIN AND SPARFLOXACIN ON HUMAN PLATELET-AGGREGATION

Platelet aggregation is inhibited by high concentrations of most antib iotics. For this reason it is important to evaluate the effects of new antimicrobial agents on platelet aggregation. Lomefloxacin and sparfl oxacin are new difluorinated quinolone antimicrobial agents. The aim o f this work was to evaluate in vitro the effects of lomefloxacin and s parfloxacin on adenosinediphosphate (ADP) and collagen-induced human p latelet aggregation. Our data showed that both antibiotics (lomefloxac in and sparfloxacin) at therapeutic doses did not inhibit in vitro hum an platelet aggregation. Lomefloxacin, only at the highest tested conc entration (1 mg/ml), which is far higher than the clinically achievabl e one, significantly (P<0.05) inhibited collagen-induced platelet aggr egation. Sparfloxacin also caused inhibition of collagen and ADP-induc ed human platelet aggregation only at the highest tested concentration (0.01 mg/ml), which is higher than that reached in vivo. These findin gs suggest that therapeutic doses of lomefloxacin and sparfloxacin do not affect human platelet aggregation.