• question-icon

    Which medication interferes with Clonazepam?

Posted on Thu, 13 Jul 2017 in Drug Abuse
Question: I take clonazepam for PTSD. Both my urine and blood tests were negative for the drug. I am wondering if another medication I am taking (especially one that is metabolized in the CP450 system) is washing the clonazepam out of my system so that it does not show up. The meds that I take in the 450 system include topiramate, nortriptyline, and pristiq. I have been taking clonazepam for 5 years and my new doctor is going to cut me off completely because of the testing. Any thoughts?
Answered by Dr. Matt Wachsman 28 minutes later
Brief Answer:
Several points.

Detailed Answer:
First if it is the dipstick test, then it is not very accurate and literally anything might happen. It should be verified with a mass spec. test. Then, there are several things that might interfere. Mostly these are unlikely to be present (bleach). Some of these drugs have a similar shape in some fashion to clonazepam so I wonder if they might trip up the test.Oxaprozin (Daypro), sertraline (Zoloft) cause false positives for benzo's. If they overscreened out the benzo's because of the closely related nortryptiline or pristiq then it would have been MADE negative.
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
Follow up: Dr. Matt Wachsman 7 minutes later
Would you believe this would happen in serum as well?
Answered by Dr. Matt Wachsman 8 minutes later
Brief Answer:
ohhhh.... serum.......

Detailed Answer:
Drugs clear faster from serum than they do from urine. It's a question of the effect. p450 increases the rate of clearance of a drug by maybe half. Urine testing generally has 20 to 1000 fold more sensitivity than the drug level. First, the drug disappears from the serum with a half life of 3 to 5 hrs. and 15 hrs is a long time for serum levels.It's a question of how high your particular level is compared to how low it can go and still test positive. If it is 100 fold, then it is hard to miss. If it is 2 fold.....heck food might change it (barbecue and grill increases p450 .. one of many examples).
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
Answered by
Dr. Matt Wachsman

Addiction Medicine Specialist

Practicing since :1985

Answered : 3703 Questions


The User accepted the expert's answer

Share on

Recent questions on  Sertraline

doctor1 MD

Hello I started taking 25mg of sertraline over three weeks ago. Had unprotected sex just over two and noticed at the same time that I started...

doctor1 MD

Hi..I have slowly decreased Serlift 50 to 25 mg and now gradually stopped. I am having dizzyness and increased appetite...so is this normal? I am...

doctor1 MD

Hi dr Iv been getting headaches for a couple of weeks now plus feeling week can t sleep probly and can t concentrate and feel sleepy I m on Zoloft...

doctor1 MD

I am over weight and have very heavy feeling legs and numbness/tingling in them. I sit for long hours in my job. I have anxiety issues and take...

doctor1 MD

i have crirrocis quit drihking 2years but i have bad itching

doctor1 MD

Hi my name is XXXXXXX I take trazodone, gabapentin and duloxetine HCL DR, with oxycodon-acetaminophen7.5-325 witch I have to drug test for. I was...

doctor1 MD

I have anxiety attacks, fatigue and major depression , I am hot and cold, sick to stomach but no vomiting . Thyroid tests (THS, T3, T4) are normal....

Get personalised answers from verified doctor in minutes across 80+ specialties

180 Doctors Online

By proceeding, I accept the Terms and Conditions

HCM Blog Instant Access to Doctors
HCM Blog Questions Answered
HCM Blog Satisfaction
Questions Answered By Dr. Matt Wachsman
  • Q - Is there any interaction between Morphine and Gabapentin?

  • Q - Can the presence of Oxycontin be detected in urine?

  • Q - Can Oxycodone be taken for wrist and back pain?

  • Q - What causes spitting of black mucus?

  • Q - How can Meth be flushed out of the system?

  • Q - Would Adderall show up in a urine test?

  • Q - What is the differece between Oxycontin and Oxycodone?

  • Q - What causes pain after knee replacement surgery?

  • Q - How long can i take Xanax for anxiety?

  • Q - Are Omega 3 supplements effective in helping muscle recovery after a...