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A. Schuyler, NP
A. Schuyler, NP, Nurse Practitioner
Category: Health
Satisfied Customers: 16239
Experience:  Board Certified NP, MS, RN. 25 years private practice & hospitalist
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I just started taking Klonopin and have a toxicology drug screen

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I just started taking Klonopin and have a toxicology drug screen 5 days after starting the drug. My question is this. I know that a benzos window for therepeutic levels is 1-10 days. Since I will fall right in the middle, will the 7 amino clonazepam metabolite show up because I was using a decent dose of klonopin unprescribed up until roughly 3.5 to 4 weeks ago. Basically does the doctor have to ask for this or does the lab automatically provide this information. To sum it up.. will I be caught and if I am can they tell how much I was using and when approximately when I took the last dose prior to the legal dose given by prescription in that 4 week interim?
Hi and thank you for your question. The answer depends upon the reason for the toxicology test. If the Dr is looking for long term use he will order the test necessary to determine that, but 4 weeks is a good bit of time as it generally takes about that long to completely clear your body. I don't think you will be "caught" and no they can not tell specifically how much you have taken, but they can predict how recently it was taken, but since you have an RX for it now, you shouldn't run into any trouble at all. I hope this informationhelps yuo, if so, please click accept. Thank you and I wish you the best! :-)
Customer: replied 7 years ago.

It states in much literature that long time chronic users that it can take from 4 and up to 6 weeks. That being said, how can you be sure that a lab does not also check for metabolites since these "may" be present in the urine. I need a toxicologist to answer this question as so very much is on the line. Check out This lab is no joke. Look under the pain management and the toxicology etc. I really want a toxicologist. Thank you so much though Camille for your help it was appreciated. This is a very intricate and difficult question that needs a toxicolgist only. Thanks again




Customer: replied 7 years ago.
Can I ask what is taking so very long? Perhaps my request of a toxicologist was too specific. I really need help here. I have been waiting 3.5 hours with the time change of the changing of the clocks back one hour. Please any medical professional... give it a shot!
Customer: replied 7 years ago.
No Camille,,, I did not Accept your answer and they were locating another professional. sorry. How do I get back to get another professional to help me? Thank you for trying though. I need a physician
Customer: replied 7 years ago.
I will even pay the highest amount allowable for the correct /non vague answer. You name the price. I m serious



First of all, drug screens don't tell quantities of anything. The screens are designed so that a certain level will trigger a positive reaction. Once there is a positive reaction, the sample is supposed to be sent to the lab for confirmation testing via GC/MS (gas chromatography/mass spectrophotometry) which can detect an exact level. The GC/MS positive level is lower than the screening level because the equipment is a lot more accurate. Still, the lab isn't concerned about your exact level unless it has been ordered for confirmation of your use of a prescription drug. For an employment drug screen, for instance, it is still reported either "negative" or "positive." Once the Medical Review Officer from the lab contacts you and is confident you have a prescription for whatever is found in the sample, the report to the employer is still listed as "negative."


If this is a test required by your provider to confirm that you are taking the two drugs prescribed, then you need to know that the metabolic rate of each person is different and they really will not be able to determine level of metabolites from the clonazepam you took 3.5 to 4 weeks ago versus those you took last week. Clonazepam has huge variation in elimination half-life which makes absolute tracking of when you took your medication unfeasible. If you are taking the current clonazepam according to directions, you will be fine.




A. Schuyler, NP, Nurse Practitioner
Category: Health
Satisfied Customers: 16239
Experience: Board Certified NP, MS, RN. 25 years private practice & hospitalist
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