<prompt> Sterile pyuria may occur due to: March 2007LignocaineParacetamolPhenytoinCocaine  <response>: Ans. B: Paracetamol Pyuria refers to urine which contains pus. It is defined as the presence of 10 or more neutrophils per high power field of unspun, voided mid-stream urine. Sterile pyuria is urine which contains white blood cells pus while appearing sterile by standard culture techniques. Sterile pyuria is listed as a side-effect from some medications such as paracetamol acetaminophen. 