RT Journal Article SR Electronic T1 Urine opiate screening: false-positive result with levofloxacin JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 1644 OP 1645 DO 10.1503/cmaj.091508 VO 182 IS 15 A1 Qaiser Shafiq A1 Anand Mutgi YR 2010 UL http://www.cmaj.ca/content/182/15/1644.abstract