Comparison of false-positive reactions for amphetamine analogs after maoto treatment using two urinary drug-screening kits

Aims Ephedra preparations are known to cause a false-positive reaction for amphetamine analogs when a Triage® kit is used for urinary drug screening. Maoto, a traditional Japanese herbal medicine that consists of Ephedra herb, cinnamon bark, apricot kernel, and Glycyrrhiza, is used for the treatment of colds and influenza. We compared two urinary drug-screening kits for false-positive reactions for amphetamine analogs after treatment with maoto from five different manufacturers over 12 h. Methods Six healthy adult volunteers received five different preparations of maoto in random order. One packet of maoto was given on each study day. Urine samples were collected before treatment, and at 3, 6, 9, and 12 h after drug treatment. Two urinary drug-screening kits (Triage® and Medical Stat®) were used for testing. Results Twenty-nine of 30 samples produced a false-positive reaction for amphetamine analogs using the Triage® kit at 3 h after treatment. No significant difference was observed among the products of the five pharmaceutical companies (P = 0.5771). All samples produced a negative reaction using the Medical Stat® kit. Conclusions Urine samples that gave false-positive reactions with the Triage® kit gave negative reactions with the Medical Stat® kit. This suggests that comparison of results from the Triage® kit and the Medical Stat® kit may be useful in screening urine samples for amphetamine analogs. The quality of maoto from five pharmaceutical companies appears to be the same with regard to interaction with the drug screening tests, adverse effects, and excretion in the urine.