Take precaution with choice of pastry: poppy seed-containing products cause significantly positive results in urine drug tests
Authors: Wilson Rebecca , Hoofnagle Andy , Laha Thomas , Baird Geoffrey , Liao Hsuan-Chieh 
Published: November 2023

Background

Chronic pain management programs utilize urine drug testing to ensure patient compliance. Because treatment can be discontinued if diversion or misuse occurs, it is imperative to carefully interpret each urine drug screen, particularly with respect to potential interferences and exposure to opioid-containing foods. Poppy seeds, derived from the opium-producing poppy Papaver cominferum L., are used widely in food products. While the seeds themselves do not contain opiates, during the harvesting process, the seeds can be contaminated with poppy latex, which does contain numerous alkaloids, including morphine and codeine. Published guidelines suggest urinary codeine concentrations exceeding 300 ng/mL, together with a morphine-to-codeine ratio &lt;2, were most consistent with codeine use, effectively ruling out poppy seed ingestion.

Methods

To assess the validity of these guidelines, we performed an internal quality improvement project, which consisted of 15 participants split into three groups. Each group consumed one of three different poppy seed-containing food products (i.e., poppy seed muffin, poppy seed bagel, or poppy seed roll). Participants collected urine samples midstream at baseline and at 3, 6, and 24 hr after ingestion. Opiates in urine were qualitatively detected via immunoassay (Beckman Coulter AU 680) and quantified by liquid chromatography-tandem mass spectrometry.

Results

For the group of participants that ingested a poppy seed roll, which contains a thick paste made from poppy seeds, all urine specimens at all time points had positive opiate immunoassay results, while the group of participants that ingested a poppy seed muffin had positive immunoassay results only at the 3- and 6-hr time-points. In contrast, all but one participant for all time points after consumption of a poppy seed bagel had negative immunoassay results. Codeine and metabolites were observed in all three groups; however, codeine concentrations were significantly higher after ingestion of a muffin or a roll, notably resulting in levels well above 1,000 ng/mL and 10,000 ng/mL of codeine and codeine-6-glucuronide, respectively. Codeine:morphine ratios ranged from 100 to 250:1 in poppy seed muffin and roll groups at 3- and 6-hour time points. There was significant variability in urine opiate concentrations among all participants in each group at each time-point.

Conclusions

Although urine opiate concentrations vary due to the metabolism of the individual as well as the origin, processing, and preparation of the poppy seed product, it is clear that previously established guidelines for interpreting urine codeine concentrations may no longer be appropriate to rule out poppy seed ingestion. When evaluating urine drug test results for chronic pain management, providers should interpret results with caution and ultimately recommend that patients generally avoid poppy seed products to prevent the risk of care mismanagement.