Does naloxone cause a positive urine opiate screen?

Abstract

To determine whether the excreted metabolites of naloxone hydrochloride cause positive urine toxicologic screens for opiates. Prospective, randomized, double-blinded human protocol. Urban Level I military emergency department. Fourteen adult volunteers who took no routine medications, were not pregnant, had no known sensitivity to naloxone, and who were negative for a pretest urine and serum toxicologic screen. We administered either 2 or 4 mg IV naloxone to 14 subjects. Urine drug screening was obtained before administration and at 60 minutes, 6 hours, and 48 hours after administration. All urine drug screens using the enzyme-multiplied immunoassay technique were negative for opiates at both dosage levels. The sample size of 14 yielded a power of more than .99 to detect the difference between positive and negative samples. Although the metabolites of naloxone hydrochloride are similar in structure to oxymorphone and are excreted in human urine for several days, naloxone was not associated with a positive enzymatic urine screen for opiates.