Extended urinary opiate detection following ad libitum ingestion of poppy seed pastry

The interpretation of urine drug test results is complicated by the potential for poppy seed ingestion to yield opiate concentrations above standard cutoffs. US federally regulated workplace drug testing programs have adjusted thresholds over time to mitigate this confounder, but the introduction of low cutoffs in clinical settings has reintroduced interpretive challenges. Fifteen adult participants consumed, ad libitum, a portion of a poppy seed kolachi. Urine samples were collected over 5 days and analyzed for codeine and morphine. Detection windows were evaluated across cutoffs ranging from 4000 ng/mL to the assays' limits of detection (8 ng/mL codeine; 10 ng/mL morphine). Opiate detection duration was inversely related to cutoff. At the 4000 ng/mL cutoff, eight participants were codeine-positive at 8 h, with two participants remaining positive at 24 h. At this cutoff, a single participant was morphine-positive through the first 12 h. At 2000 ng/mL, only codeine remained detectable, in a single participant, at 48 h. At 300 ng/mL, seven participants were opiate-positive at 48 h (only codeine, n = 4; only morphine, n = 2; codeine and morphine, n = 1), and four remained positive at 72 h (only codeine, n = 2; only morphine, n = 2). At 50 ng/mL, five participants were opiate-positive at 96 h (only codeine, n = 2; only morphine, n = 2; codeine and morphine, n = 1). Four participants continued to produce detectable opiate concentrations at 108 h (codeine only, n = 1; morphine only, n = 1; codeine and morphine, n = 2). A single ingestion of a commercial poppy seed kolachi produced urinary opiate concentrations exceeding cutoffs from 4000 ng/mL down to the assays' limits of detection, with positivity persisting up to 108 h. These findings underscore the need for cautious interpretation of positive results-especially in settings using low cutoffs-and support the potential utility of adjunctive markers such as thebaine.