Frequently Asked Questions What is the difference between Methamphetamine and Amphetamine? Posted on December 15, 2015December 10, 2020 by rapiddetect Both are potent symphathominetic agents. Methamphetamine is the parent drug. It metabolizes into amphetamine in the body. Methamphetamine and/or Amphetamine are excreted in the urine. rapiddetect What are the screening cut-off levels? Are Morphine, Opiates, and Heroin the same kind of drug?