Can lidocaine cause a false positive for cocaine on a drug test?
Jan 17, 2020 · Will lidocaine cause a positive drug test? CONCLUSION: The present study found no evidence that lidocaine or norlidocaine are capable of producing false positive results on standard cocaine urine immunoassays.
Does lidocaine show up on a urine drug screen?
Jul 19, 2020 · Background: Individuals who have tested positive for cocaine have claimed that lidocaine, or its primary metabolite, norlidocaine (monoethylglycinexylidide (MEGX)), have caused false positive results for the cocaine metabolite benzoylecgonine (BE) on urinary immunoassay testing. Objective: The goal of the study was to determine if lidocaine exposure from routine …
Can local anesthetics cause a false positive drug test?
Nov 23, 2010 · christineATU 24 Nov 2010 As Marjorie indicated, lidocaine should not cause a positive for cocaine in a UA. False positives are so common, they should develop a more accurate, cost efficient system so people do not lose their jobs, denied new jobs, have probation revoked, lose a custody case, and end up with a bad reputation as a drug abuser.
Does lidocaine mimic cocaine?
Mar 26, 2021 · People who have tested positive for a drug test have claimed that Lidocaine patches have caused false-positive results. Lidocaine gets metabolized quickly by the liver into several metabolites and is mainly excreted by the kidneys.
What causes false positives in a drug test?
False positives are caused by: *Nasal decongestants such as Dristan, Neosynephren, Vicks Nasal Spray, and Sudafed, which cause false positives for amphetamines. *Poppy seeds like those on a dinner roll, which cause false positives for opiates. Even the highest-quality test currently available, the GCMS test, still confuses poppy seeds with heroin.
Why are false positives so common?
False positives are so common, they should develop a more accurate, cost efficient system so people do not lose their jobs, denied new jobs, have probation revoked, lose a custody case, and end up with a bad reputation as a drug abuser.
Why is a drug patch better than a urine test?
Drug test patch provides better results than urine test because it can detect the consumed drug as well as its metabolite i.e. the product of metabolism of the parent drug. Whereas urine tests can reveal only the metabolite. So if the person consumes the drug occasionally, a urine test cannot capture the drug because it is already metabolized.
What is the advantage of a drug patch?
In comparison to a urine test, a drug test patch has the advantage of a large detection period. Urine test involves strips which give off immediate results. If fast clearing drugs are used by a person they will not be detected by a urine test. But the drug test patches can be used for a longer duration.
Why are sweat patches important?
Sweat patches provide a reliable source of evidence because once attached they cannot be removed or changed as they have a unique identification number. Whereas, urine test results can be easily manipulated.
Is it easier to apply sweat patches?
Application of sweat test patches is easier and quicker. Unlike the urine test where urine has to be collected and has to be analyzed using the strips, attaching the test patches is more hygienic. However, if the patch test results are positive then it has to be further confirmed by a urine test.
What is urine drug screen?
Urine drug screen (UDS) immunoassays are a quick and inexpensive method for determining the presence of drugs of abuse. Many cross-reactivities exist with other analytes, potentially causing a false-positive result in an initial drug screen.
Can lidocaine cause false positives?
Background Individuals who have tested positive for cocaine have claimed that lidocaine, or its primary metabolite, norlidocaine ( monoethylgly cinexylidide (MEGX)), have caused false positive results for the cocaine metabolite benzoylecgonine (BE) on urinary immunoassay testing. Objective The goal of the study was to determine if lidocaine exposure from routine medical procedures can result in false positives on a commercially available cocaine immunoassay urine drug screen (UDS). Methods We performed a cross-sectional observational study of patients receiving lidocaine as part of their regular care. Standard immunoassay drug screens and confirmatory liquid chromatography-mass spectrometry (LC-MS) were performed on all urine samples to assess for MEGX and BE. Results In total, 168 subjects were enrolled; 121 samples positive for lidocaine were ultimately included for analysis. One hundred fourteen of the 121 were also positive for MEGX. None of the 121 were positive for cocaine/BE on the UDS (95% CI), 0–3.7% for the full sample and 0–3.9% for the 114 who tested positive for MEGX. Conclusion The present study found no evidence that lidocaine or norlidocaine are capable of producing false positive results on standard cocaine urine immunoassays.
