Benzoylecgonine is a major metabolite produced by the liver after cocaine use. As BZE is unique to cocaine it’s also known as a “fingerprint metabolite”.
As cocaine is metabolised by the body rapidly, it’s broken down by three processes known as esterases, de-methylation and ecgonine formation. It’s the process of de-methylation that converts around 40% of the cocaine into benzoylecgonine.
What are the Important Facts to Know about Benzoylecgonine?
If you’re concerned about a potential drug driving offence, exploring the specified limits of Benzoylecgonine (BZE) can help you understand the law and give you the information you need to build a good defence.
Here are some key points about this major metabolite
- Benzoylecgonine does not cause any impairment. It is completely inactive. Even the highest levels of BZE will not affect the body. (400-800mg)
- BZE will almost always be detected in your body.
- BZE is present in your system for much longer than cocaine, which is why it is included in legal limits.
- The police test for Benzoylecgonine as cocaine is likely to be eliminated from your system before you have tests at a police station. By testing for BZE, you are less likely to avoid prosecution.
Is There a Legal Limit for Benzoylecgonine?
Drug driving limits on certain controlled drugs including Benzoylecgonine are extremely low to reflect a “zero tolerance” approach to driving with illegal drugs which has now been adopted in England and Wales.
| Illegal Drugs | Legal Limit |
|---|---|
| Benzoylecgonine | 50 µg/L of blood |
How Long Will Benzoylecgonine Stay in Your System?
Cocaine usually clears from your bloodstream within 4-6 hours. Benzoylecgonine, however, can be detected up to six days after being used.
Within 30 minutes of cocaine use, Benzoylecgonine becomes detectable in the blood. And as time goes on, these levels will steadily increase for the next 2-3 hours. For example, if you were to take a “line” of approximately 35mg of cocaine at around 11 pm, Benzoylecgonine would be easily detected by 11.30. Then by 2.30 am the levels of BZE would have risen to around 130mg, easily surpassing the drug-driving limit of 50 micrograms.
Are There Any Drug Driving Defences for Benzoylecgonine?
If you’re concerned about being charged and a subsequent criminal record after being arrested for drug driving, then being aware of procedural issues concerning the preliminary and evidential test procedure, the taking of the blood specimen, its handling and the reliability of the analysis itself will be key to building a strong defence and avoiding disqualification from driving.
The Increase of Benzoylecgonine Levels over time
Did you know that your blood samples are often stored by laboratories for weeks or months at a time? Due to the oversubscription of some services and large backlogs at the laboratory, it may take some time before samples are analysed. Samples may not be refrigerated correctly and/or poorly preserved whilst waiting for analysis which can have a bearing on the reliability of the analysis.
As more time passes, the quality of the samples will deteriorate. This is a natural reaction that cannot be prevented and can only be slowed down by adding preservatives to the sample in an attempt to conserve it. While the levels of other drugs such as cannabis or methadone morphine will deplete over time along with the quality of the sample, Benzoylecgonine is different. We know that cocaine will convert into BZE which means the longer your sample is stored before being analysed, even if it is refrigerated, the higher the levels of Benzoylecgonine will be when it is finally analysed.
As cocaine rapidly develops into Benzoylecgonine, these samples must be taken properly and preserved correctly. There have also been cases where levels of BZE were proven to be below the legal limit when the blood sample was taken, providing the police with a result that does not properly reflect the amount of drug in the blood at the relevant time.
Dental Treatment and Accidental Exposure
As a major metabolite of cocaine, if BZE is found in your system it most certainly suggests some previous cocaine use – after all this byproduct isn’t found or produced in any other way. However, if you have recently received dental treatment and been given Benzocaine to help manage mouth pain or as a topical solution then there is a potential defence that an inexperienced lab worker, who is running your blood samples has mistaken Benzocaine for Benzoylecgonine.
If you have recently received dental treatment, it’s important to explain this to your legal representative.
Quality Control of Samples and Testing
Did you know that labs that undertake this kind of testing for authorities not only need to have specific licensing but they must also adhere to strict quality assurances? Due to the shockingly high margin of error that comes with drug testing, levels of accuracy and performance are stringently measured in these labs to ensure precision and effective results.
Interestingly, there have been reports of UK labs having their United Kingdom Accreditation Service (UKAS) accreditation revoked due to incorrectly calculated results and persistent “anomalies”. While we know that Benzoylecgonine can only be produced when cocaine has been used, it’s important to know that some prescription medicines also produce similar metabolites. When a UK lab doesn’t uphold the right levels of stringent testing, quality control or assurance, it can highlight the possibility of inaccuracies and errors being made. In other words, a prescription drug may be mistaken for Benzoylecgonine!
FAQs about Benzoylecgonine
No. This is not the case. Benzoylecgonine does not cause any kind of impairment because it is an inactive metabolite. However, the presence of Benzoylecgonine does indicate the use of cocaine.
No. Because Benzoylecgonine is a byproduct that is unique to cocaine use, any prescription medicines or other drugs you take will not impact its levels in your bloodstream.
The minimum period of disqualification that can be imposed is 12 months. Magistrates apply guidelines when deciding the sentence that should be imposed for drug driving. There are three categories within the sentencing guidelines for driving in excess of the limit for benzoylecgonine of which category 1 is the most serious and category 3 the least serious.
In a case where only benzoylecgonine but no other drug has been detected, the vehicle being driven is not a goods vehicle/HGV/driven for reward and where there is no evidence of impairment or unacceptable manner of driving, the offence is likely to be placed in category 3. In such cases, the guidelines suggest a 12-16 month disqualification and a fine for a first-time offender. If there is a previous conviction for drink/drug driving within the last 10 years, the minimum disqualification that must be imposed will be three years.
If the vehicle being driven was an HGV or being driven for reward and/or there is evidence of an unacceptable manner of driving, the offence is likely to be placed in a higher category in which case the disqualification may be longer. In the most serious cases, a custodial sentence may be imposed.
If you plead not guilty to the charge and challenge the reliability of the analytical result, you will be entitled to be served or given an opportunity to inspect the analytical data pack upon which the results of the analysis are based.
Once the data has been supplied, an independent forensic toxicologist may be able to identify issues that cast doubt upon the reliability of the reported Benzoylecgonine levels in your blood and the way the samples were handled. Alternatively, in a case where the reported result is only marginally above the prescribed limit, it may be possible to argue that biotransformation of the drug from cocaine to benzoylecgonine in between sampling and analysis means that the Court cannot be sure that the reported result is reliable.
If you’re charged with this kind of drug driving offence, it’s important to seek legal advice as soon as possible, preferably from a solicitor who specialises in drug driving law. Then the evidence can be reviewed and you will be advised on the best course of action to take.
