Ofloxacin causes false-positive immunoassay results for urine opiates

Immunoassay drug screening tests are usually used as a control during metha done maintenance programmes, to check cleanliness of drugs during detoxific ation treatment and abstinence programmes. False-positive results can have catastrophic consequences for the patient, as shown in the case report. Fal se-positive results were reported for opioids following ofloxacin or rifamp icin and for LSD following mucolytic. Since inpatient and outpatient units usually employ an urine quick test (immunoassay), positive results should b e checked with gas chromatography/mass spectroscopy (GC-MS) or high pressur e liquid chromatography (HPLC) before conclusions from the positive urine s creening results can be drawn.