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Family Physician
Family Physician, Board Certified MRO
Category: Drug Testing
Satisfied Customers: 12816
Experience:  Medical Review Officer - Physician Trained and certified in drug test interpretation
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multi-drug screen test (coc/amp/thc/opi/pcp)

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I just took a home multi-drug screen test (coc/amp/thc/opi/pcp) and tested positive for amphetamines. I HAVE NOT taken any any illicit drugs. I currently take the following daily drugs: Bupropin HCL 450 MG XL Vivanse 70 MG Omeprazole DR Tab 20 MG Mens Health multi-viatamin 2000 MG Omega 3 Fish Oil I have taken these drug tests periodically for the last year & never had a positive result. The only other drugs that I have taken that are out of the ordinary are: Flexeril & Hydrocodone (Also Advil & Backaid Max with acetaminophen & pamabrom) I took these drugs the last few days because I was having severe back pain. My question is could these prescription drugs have caused my false positive? If so, why have I not ever tested positive before now? What do I do now? Thanks
There are a number of potential causes of false positive drug tests that use immunoassay technology such as the home test that you did.

Bupropion can cause false positives, but Vyvanse will cause a TRUE positive for amphetamine since it metabolizes to d-amphetamine which is excreted in the urine.

The concentration of the the drugs in your urine vary depending on time since last dose and the amount of fluid you have consumed. If the concentration is below the sensitivity of the test, you will get a "false negative" despite using the medication which should cause a true positive.
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Customer: replied 5 years ago.
So now what can I do to prove that I have not taken meth?
Amphetamine and methamphetamine are 2 different drugs - chemically similar. If the specimen is sent to a laboratory for additional testing (GC/MS) - the laboratory can differentiate between amphetamine and methamphetamine.
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