Urine Drug Testing for Patients on Vyvanse

Understanding Vyvanse Metabolism

The American College of Obstetricians and Gynecologists notes that Vyvanse (lisdexamfetamine) is a prodrug that is converted to dextroamphetamine in the body, and patients should test positive for amphetamines on a standard immunoassay screen 1
The American Academy of Pediatrics recommends that a positive amphetamine screen is expected for patients taking Vyvanse as prescribed, reflecting therapeutic use rather than illicit drug use 2

The Centers for Disease Control and Prevention recommends ordering a standard immunoassay urine drug panel that includes amphetamines, opioids, benzodiazepines, cocaine metabolite, and tetrahydrocannabinol (THC) for initial screening 3, 4
Annual testing is reasonable for monitoring adherence and detecting concurrent substance use that increases risk, according to the Centers for Disease Control and Prevention 3, 4

A positive amphetamine immunoassay is the expected finding for a patient taking Vyvanse as prescribed, and documentation of the patient's Vyvanse prescription before testing can avoid misinterpreting therapeutic use as illicit drug use, as noted by the American Academy of Pediatrics and the Centers for Disease Control and Prevention 2, 6
It is crucial not to assume a positive amphetamine test indicates illicit drug use, as patients taking prescribed amphetamines will test positive, according to the American Academy of Pediatrics 2

Standard drug screens will miss synthetic cannabinoids, ketamine, GHB, and many specific benzodiazepines like clonazepam, and targeted testing should be requested if use of these substances is suspected, as recommended by the Centers for Disease Control and Prevention and Praxis Medical Insights 6, 7

The Centers for Disease Control and Prevention suggests explaining to the patient before testing that urine drug screening is intended to improve safety and confirm medication adherence, and discussing expected results and any other medications or substances that might appear 3, 4, 6
If unexpected results occur, discussion with the laboratory or toxicologist before making clinical decisions is recommended by the Centers for Disease Control and Prevention and Praxis Medical Insights 6, 7, 5

The Centers for Disease Control and Prevention and Praxis Medical Insights recommend performing immunoassay first, then ordering confirmatory testing only when results are unexpected or will directly inform clinical decisions, to reduce unnecessary costs 5, 6