I took ONE 50mg Vyvanse (lisdexamfetamine) Saturday, I have a drug test Monday, I've never taken this drug before. I play sports everyday, will I pass my drug test?

Maybe. Vyvanse (lisdexamfetamine) is converted to amphetamine. The conversion takes place slowly, and continues even 24 hours after ingesting the drug. If you were tested on Sunday, you would definitely have amphetamine in your urine. But amphetamine is cleared very quickly, so once the Vyvanse (lisdexamfetamine) has been converted, the amphetamine will quickly disappear. Will it disappear by Monday? That's a toss-up.