In observational analyses , use of ciprofloxacin and piperacillin/tazobactam predicted risk of relative thrombocytopenia ( vs. cefuroxime , RR : @ -LSB- @-@ @ -RSB- ; @ -LSB- @-@ @ -RSB- , respectively ) , however only ciprofloxacin were associated with a reduction in absolute platelet count ( p = @ ) .