Question about some lab results

[TLO]

www.chiefsplanet.com is where I head to get all of my medical questions answered! (Seriously though I know we have some people here knowledgeable about this stuff)

Went in to do my yearly drug screening due to me taking a benzodiazepine on a regular basis about a week ago. Got the results a day later along with a call from my doctor saying that my test came back negative for benzos. They asked me if I had been taking the medication as prescribed, which I have. They said no big deal, we'll just redo the test.

Did the sample again yesterday, and again it was negative. The doctors office isn't open today so I'm not sure what the deal is.

Anyone know why I'd be coming up negative on the screening? Klonipon is the drug, if that helps any.

[SupDock]

Yeah, assuming all things you have said being true, this is a false negative.

Most likely from hook effect, and mass spectrometry should solve the issue.

There really isn’t a therapeutic window for Benzos, as it is generally symptoms driven. There are dosing guidelines though

[TLO]

Originally Posted by SupDock

Yeah, assuming all things you have said being true, this is a false negative.

Most likely from hook effect, and mass spectrometry should solve the issue.

There really isn’t a therapeutic window for Benzos, as it is generally symptoms driven. There are dosing guidelines though

Well I'm going to sit down 1 on 1 with my doctor on Wednesday and discuss it with him.

I have printed off various reliable/ well respected resources to show him why a mass spectrometry test is warranted.

I'm also taking in my bottle of medication.

If they still won't do the MS test...

[Coach]

My suggestion is, if they are not doing what you are asking them to do (and from what I am understanding, this isn't like a very dangerous stuff going on), I would say find a different doctor.

Some doctors are better than others and may have a better understanding of your case.

[TLO]

Originally Posted by Coach

My suggestion is, if they are not doing what you are asking them to do (and from what I am understanding, this isn't like a very dangerous stuff going on), I would say find a different doctor.

Some doctors are better than others and may have a better understanding of your case.

Yeah man, but the wait list for a psychiatrist is CRAZY.

[dlphg9]

Originally Posted by TLO

See the weird thing is that my number came back as 791 after they did the MS test last year.

This may be the problem. Found this in a study and have seen it in several different sources.

The immunoassay often uses an antibody to
oxazepam, a metabolite of diazepam and chlordiazepoxide.6,7
This antibody has relatively low cross reactivity with
clonazepam and lorazepam and is therefore less likely to be
detected reliably.

This is a different lab, but this is what Aegis Labs says

"A patient taking alprazolam, clonazepam, flurazepam, or lorazepam will not test positive for benzodiazepine metabolites on an Aegis report."

https://www.aegislabs.com/resources/...l-update/dec19

[TLO]

Originally Posted by dlphg9

This may be the problem. Found this in a study and have seen it in several different sources.

The immunoassay often uses an antibody to
oxazepam, a metabolite of diazepam and chlordiazepoxide.6,7his antibody has relatively low cross reactivity with
clonazepam and lorazepam and is therefore less likely to be
detected reliably.

This is a different lab, but this is what Aegis Labs says

"A patient taking alprazolam, clonazepam, flurazepam, or lorazepam will not test positive for benzodiazepine metabolites on an Aegis report."

https://www.aegislabs.com/resources/...l-update/dec19

I have that study printed off already to show my doctor.

Well, one of the numerous studies I found that say that exact same thing.

[dlphg9]

Originally Posted by TLO

I have that study printed off already to show my doctor.

Well, one of the numerous studies I found that say that exact same thing.

Here's a good one too

https://www.google.com/url?sa=t&sour...J-clz4YxDQQ51S

False positive rates for benzodiazepine immunoassays are relatively low (<5 percent).
However, most benzodiazepine immunoassays used for screening are susceptible to false
negative results. The false-negative rate for benzodiazepines in an immunoassay screen is
approximately 25-30 percent, and is particularly problematic for clonazepam. One reason
for false-negative clonazepam results is that the drug appears in the urine almost entirely as
7-aminoclonazepam, a metabolite that is not detected by many commercial immunoassay
screens. A similar challenge exists for some other extensively metabolized benzodiazepines.
Concerns about false-negative results in confirmation/quantitation tests for
benzodiazepines also exist due to variation among laboratories in the cutoff concentrations
(sensitivity), the actual analytes detected, and the sample preparation methods. Regarding
sample preparation, some laboratory methods includes a sample pretreatment reaction prior
to analysis that liberates glucuronide metabolites (e.g., hydrolysis). Hydrolysis pretreatment
will improve detection of most benzodiazepines. Inclusion of multiple benzodiazepine
metabolites will also improve detection of benzodiazepines in urine confirmation/
quantitation tests.

[TLO]

Doctor flat said no to any other test. They have to follow the policies and procedures set by the administration. Anyone have any suggestions?

[TLO]

Healthcare is ****ed up