Study objective: To determine whether the excreted metabolites of naloxone hydrochloride cause positive urine toxicologic screens for opiates.
Design: Prospective, randomized, double-blinded human protocol.
Setting: Urban Level I military emergency department.
Participants: 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.
Interventions: 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.
Results: 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.
Conclusion: 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.