The Effects of Herbs, Spices and Foodstuffs on Urine Screens for Drug Abuse by Immunoassay

Drug abusers are highly motivated to obtain negative results on urine drug abuse screens and may attempt tosubvert the process by trying to adulterate their samples. One of the processes thought to make drug abusersescape a positive urine drug screen is the ingestion of different herbal and other foodstuff products along withdrug intake. This project aimed to evaluate the effects of common traditional herbal drinks, spices and somefoodstuffs in Jordan on producing false negative urine drug screens for opiates, amphetamines and cannabinoidwith fluorescent polarizing immunoassay (FPIA). Thirty one products were divided into two groups;the firstgroup’sproducts were extracted with methanol while the second group’s were extracted with water. Urine drugfree samples were spiked with each product or its extract in addition to a known concentration of opiates,amphetamines or cannabinoids. The spiked urine samples were analyzed using FPIA. It was found that none ofthe 31 products had modified the drug screens using FPIA to reduce or increase the level of the spiked drug inthe urine sample. It was concluded that these products did not produce falsenegative results with urine drugscreenings by means of FPIA as it is believed by drug abusers. However, such conclusions should be takencautiously since thisis not an idealevaluation. It would be ideal to apply such a study on normal volunteers toevaluate the actual disposition of the ingested substances and the drugs as well as their interactions within thebody, but it cannot be conducted due to ethical considerations