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Which Medication Interferes With Clonazepam?
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?
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.
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
Would you believe this would happen in serum as well?
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).
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).
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Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
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