Sean asked
Can the ADHD medication Vyvanse (lisdexamfetamine dimesylate) cause a false positive for D-Methamphetamine?
Answer
Depending on the specific drug test you are taking, yes, Vyvanse (Lisdexamfetamine) could cause a positive drug test for methamphetamine. I wouldn't say it causes a "false positive" because the drug test you are likely referring to is looking for multiple drug metabolites. Drug tests rarely are designed to detect the parent drug (i.e. non-metabolized drug) in the urine. In nearly every case, they are specified to detect known drug metabolites.
Vyvanse is metabolized in the body to dextroamphetamine (d-amphetamine), mostly in the blood. From there, d-amphetamine produces no less than 4 other metabolites, all of which could be detected in a drug test. Methamphetamine produces no less than 7 metabolites, one of which is d-amphetamine. As such, Vyvanse and methamphetamine share some of the exact same metabolites.
All of these drugs are closely related and produce similar, and in some cases the same, metabolites. Due to this, unless a drug test has a very specific sensitivity to a certain metabolite at a certain concentration, you will nearly always get a positive test for amphetamines.
If you are being tested for amphetamines, it would be prudent and wise to make the tester (or supervisor) aware of a legitimate medical prescription you are on for Vyvanse.
