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What Causes False Negative Result For Vyvanse On Drug Test?
Question: I was told by my prescribing doctor to take "drug holidays" from my vyvanse when I knew I had a few days when I wouldn't need it as much. So I have been. Well today, I went in for my monthly meeting, and they asked me to submit to a drug screen. I said sure! I had told her that I hadn't tsken it since Friday. But when the results came back and it was negative for the vyvanse. She said she wasn't going to prescribe it to me any longer. She basically accused me of selling it or doing something else unsavory. Is it uncommon for someone to test negative after not taking it for 3 days? I am 5-6 and weigh about 140.
Thank you for your time.
Thank you for your time.
Brief Answer:
It is more likely that the blood levels would drop to zero in 3 days.
Detailed Answer:
Thanks for asking on HealthcareMagic.
I have gone carefully through the details. Let me mention that the plasma elimination half-life of Vyvanse (lisdexamfetamine) typically averages to less than one hour. This means that the blood level of this medicine drops to half in less than an hour. So, in a matter of 3 days of not taking the medicine, the entire amount of drug could definitely have been cleared from your system. Therefore in my opinion it is common to test negative for vyvanase if you are off it for 3 days.
Hope that helps.
If you found my answer to be helpful, please close the thread with a positive review and a 5 star rating.
Regards
Dr. Kunal Saha
It is more likely that the blood levels would drop to zero in 3 days.
Detailed Answer:
Thanks for asking on HealthcareMagic.
I have gone carefully through the details. Let me mention that the plasma elimination half-life of Vyvanse (lisdexamfetamine) typically averages to less than one hour. This means that the blood level of this medicine drops to half in less than an hour. So, in a matter of 3 days of not taking the medicine, the entire amount of drug could definitely have been cleared from your system. Therefore in my opinion it is common to test negative for vyvanase if you are off it for 3 days.
Hope that helps.
If you found my answer to be helpful, please close the thread with a positive review and a 5 star rating.
Regards
Dr. Kunal Saha
Above answer was peer-reviewed by :
Dr. Prasad
Thank you for your response. It is very helpful. The drug screen was done by urine. Would that make a difference?
Brief Answer:
Urine test would not make a difference
Detailed Answer:
Thanks for writing back.
The urine test shows how much of the drug is being eliminated. No elimination would automatically mean that there is no residual amount left in the blood. Practically urine drug tests are more frequently done. It means all the same.
If you found my answer to be helpful, I would be glad if you close the thread with a positive review and a 5 star rating.
Regards
Dr. Kunal Saha
Urine test would not make a difference
Detailed Answer:
Thanks for writing back.
The urine test shows how much of the drug is being eliminated. No elimination would automatically mean that there is no residual amount left in the blood. Practically urine drug tests are more frequently done. It means all the same.
If you found my answer to be helpful, I would be glad if you close the thread with a positive review and a 5 star rating.
Regards
Dr. Kunal Saha
Note: For more detailed guidance, please consult an Internal Medicine Specialist, with your latest reports. Click here..
Above answer was peer-reviewed by :
Dr. Ashwin Bhandari
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