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Family Physician
Family Physician, Board Certified MRO
Category: Drug Testing
Satisfied Customers: 12816
Experience:  Medical Review Officer - Physician Trained and certified in drug test interpretation
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I am being charged with driving whilst under the influence

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I am being charged with driving whilst under the influence of drugs. When I was arrested I tested negative on alchohol and subsequent blood tests, done by the police, and one commissioned by me, returned negative for all tests conducted, but said there was a possible presence of a benzodiazepine substance.

I am looking for someone to review my files, and confirm (hopefully) that in there opinion, my impairment on the day of driving was not down to drugs. I would require someone who would be recognised by the courts as an expert, and was prepared to give a written statement.

I am on Phenelzine at the moment for anxiety/depression issues. I did take an off the net substance on the day, called Etizolam. I believe this was fake/ a sugar pill, as I have taXXXXX XXXXXepam before and encountered none of the same anxiolytic effects with the 'Etizolam'. I had taken the last valium approx 3-4 weeks prior to the incident so was wondering whether this could account for the preliminary positive. Below is text quoted from my independent analysis

"The samples were screened by immunoassay techniques for the presence of amphetamine and methamphetamines, cocaine metabolites, methadone, cannabis, opiates, barbiturates and benzodiazepines. Both samples indicated the possible presence of benzodiazepines.
As initial screening tests may give false positive results, the results need confirming by an independent technique to allow identification of the specific drug present and the amount present.
Confirmatory analysis was undertaken, which involved examining the samples for a range of commonly used benzodiazepine drugs (diazepam, temazepam etc.). In both sample cases we could not identify the presence of any of the common benzodiazepine drugs in the samples."

Many thanks for reading this
Thank you for your question:

As a medical review officer (MRO) - a physician with specialized training in drug testing - I would be happy to provide some information for you. Unfortunately, I would not be able to provide any documents to the courts in the UK, since I am based in the USA.

Your tests were negative for the tested drugs, HOWEVER, they did not test for the medication that you were taking. This medication can potentially cause driving impairment.

There is no way to say that you were not impaired due to drugs - only that you did not have measurable levels of the particular drugs tested. Your legal representative should be able to argue that since they have no proof that you had any drugs in your system, that you should be found "not guilty" of this charge.
Customer: replied 4 years ago.

Thanks for the response.


May I ask


A) In both screenings, both the police, and the independent one I commissioned, they mention "possible presence of benzodiazepines". Does the immunoessay test have a considerable false positive error rate? I take it must do as they will only say that a positive immunoessay test can only indicate a "possible presence", it cannot prove it, and that is why more detailed tests are needed.


B) I had some prescription valium about 3-4 weeks prior to the incident. Could this cause the immunoessay positive indication? however since it must have nearly been expelled from my system (I read somewhere it takes 23 days to be totally eliminated, based on its half life), then the more detailed test returned negative. i.e is it it possible for the immunoessay test to detect trace valium usage (a positive), but the more detailed test fails as it needs a higher concentration in my blood stream for a positive match.


C) I was seen by a police doctor about 6 hours after been arrested, who described me as being in an extremely impaired state. Are even large doses of Etizolam able to cause continued intoxication after 6 hours? I believe it is a short duration of action medication, so would it not have been more or less 'worn off' entirely after 6 hours?


D) Are there any medical explanations for unexplained loss of coordination and symptoms resembling intoxication? I took two etizolams several hours prior to the incident, and had been taking them at the same level for several months before without incident. I.e. Can i put forward an alternative explanation for my erratic behaviour, such as mental exhaustion, or anything else? Could you suggest some medical conditions that would have this effect


Many thanks

PS I understand I am asking for a significant level of detail, and I will of course reflect my gratitude in the tip I give you at the conclusion of our discussion.

Immunoassay tests can be "non-negative" (or "possible positive") for a number of reasons. They are NOT considered definitive. On the the confirmation tests would be considered TRUE positives.

From a scientific perspective, the immunoassay is a screening test, and is not evidence of the presence of the drug. The ONLY reason it is done is to reduce cost of testing. If the immunoassay is negative, no further testing is needed. The confirmation tests (GC/MS) are more expensive. If they had to do GC/MS on every specimen for every possible drug - the cost would be very high.

It is possible that the pills you purchased from the net - contained something other than the medicine you thought you were getting. This drug could have interacted with the prescription medication you were taking.

I am not a UK legal expert, but in the USA, you can be found guilty of impaired driving if you are impaired for ANY reason (incapable of safely operating the vehicle) including over-the-counter medications, prescription medications or even sleep deprivation. The principle is that you need to be physically/mentally capable of safely operating the car at all time. If you are not safe to drive for any reason - you can not legally drive.

My best guess, you had a adverse reaction to this pill you obtained from the net. Many of these internet purchased drugs are fakes, and contain drugs other than the ones that they claim to contain.
Customer: replied 4 years ago.



Thanks for that. The law is the same in the UK.


I understand I am asking for a level of detail of info in my prior A, B,C,D questions. I do not wish to appear rude but you only specifically answered question A.


Is it possible for you to directly address the other 3 questions also. If this is beyond the scope of the level of advice I have requested, could you let me know the level of tip you would require to answer the questions directly and in detail. I am new to this justanswers thing so please let me know if there is a way I can tip you prior to completion of our conversation.


Many thanks



I'm sorry - I got involved in the first part, and forgot about the other parts.

It is unlikely that the screening test was influenced by the Valium since the confirmation testing (for Valium) was negative.

While the medication has a half-life of approximately 3.5 hours, the main metabolite has a half-life of 8 hours - so much of the drug would still be in the body (and potentially interacting with your other prescription medication). As I mentioned, you can't be sure that the pill you obtained over the internet was in fact this medication. It could have contained something completely different.

You could of course put furth another explanation (sleep deprivation, stress, etc), however the legal principle of impairment for any reason still applies. If had been in an accident - a concussion (brain trauma) could cause confusion - but this would assume that there was a history of accident with trauma to the head.
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