Poppy Seed Consumption May Be Associated with Codeine-Only Urine Drug Test Results

Abstract

Consumption of poppy seed-containing food products can result in opiate-positive urine drug test results and may pose challenges in distinguishing poppy seed consumption from opiate administration. In this context, guidance has suggested that codeine concentrations exceeding 300 ng/mL coupled with morphine-to-codeine ratios <2 are indicative of codeine consumption and, therefore, exclude poppy seed consumption as a legitimate explanation for the test result. In recent years, we performed independent medical examinations of three individuals who produced codeine-positive/morphine-negative (300 ng/mL) forensic urine drug test results but denied codeine administration, attributing their test results to the consumption of specific poppy seed-containing food products. In the present study, 11 participants consumed one of the 10 unique poppy seed-containing food products, including the three implicated food products. Six of 33 non-baseline urine samples (18%)—representing three food products—were positive for codeine and negative for morphine at 300 ng/mL cut-offs (and therefore featured morphine-to-codeine ratios <2). This study adds to a small literature indicating that consumption of poppy seed-containing food products cannot reliably be distinguished from codeine administration based on previously published urinary opiate concentrations and ratios. An important caveat is that in none of these cases did maximum urinary codeine concentrations exceed 1,300 μg/g creatinine.