Amphetamine

How cocaine works in your body

Cocaine is a central nervous system stimulant with blocks the reuptake of dopamine and noradrenaline and serotonin. It is metabolised to benzoylecgonine (BZE) which is also tested for under the drug driving legislation but also ecgonine methyl ester both are produced in the liver.

The effects of cocaine are short acting but will depend on the dosage.

Acute Intoxication

• Fairly low doses 15 – 30mg/ 24 hours will result in:
• Rapid breathing
• Increased heart rate
• Loss of appetite
• Dilation of pupils
• Slight tremors

Higher doses will result in

• Dryness of the mouth
• Raised body temperatures
• Increased heart rate and irregular heart rhythms
• Excessive sweating
• Poor coordination/dizziness

These symptoms can last for over 12 hours.

Often users will do repetitive tasks for hours and may suffer from fluid on the lungs (pulmonary oedema) or heart attack (myocardial).

Psychological impact

• Euphoria
• Increased confidence and self esteem
• Increased energy
• Increased irritability
• Restlessness

Higher doses may result in:

• Irrational behaviour
• Confusion
• Hallucinations
• Delusional paranoia
• Psychosis
  

Longer term users will develop a tolerance and the effects will often last days with the users taking several grams daily. After this period they can often sleep for days.

Long term use has inherent dangers of anorexia, malnuitrition, vomiting, heart conditions, convulsions, coma and death.

Psychological long term use can result aggression, fatigue, physical weakness, suicidal ideation and permanent psychosis. Latent schizophrenia may be triggered by moderate use or even a single large dose.

Prescribed Amphetamine

Amphetamine was originally used for weight reduction and as an antidepressant. It is currently used for the treatment of hyper activity and narcolepsy. Methylpenidate is used for the treatment of ADHD and narcolepsy. Methamphetamine, as the I-form, is used in some formulations of “Vicks” inhalers.

There is a defence has been introduced under S5A(3) of the Road Traffic Act 1988 which states that if a drug is prescribed for medical or dental reasons and taken in accordance with any directions by the Doctor, Dentist or consultant and also the manufacturers instructions. The drugs must also be being used legally ie not prescribed to another.

Amphetamine and driving

The impact on driving is the same as other stimulant drugs such cocaine :

• Higher Risk taking: pulling out in front of vehicles, taking dangerous overtakes, driving faster
• Poor judgement: impulsive behaviour –behaves erratically when confronted with a dangerous situation.

These heightened symptoms only last a short period of time and then the after effects will kick in and these lead the following issues:

• Slower reaction time: greater distance will be travelled before reacting and there there is a increase risk of a collision.
• Lack of coordination: inabilaity to manage vehicle when driving and react appropriately to an emergency.
• Reduced concentration: miss road signs – traffic lights
• Decreased vision: “snow lights” which affect your periphal vision is common place with cocaine users which means that a driver can miss signs, fail to see pedestrians and other road dangers.

Studies have shown that very low doses in the short term can improve driving performance if tired. However, the after effects will impair driving. Generally medically prescribed drugs may affect driving performance due to the dosage prescribed so users should take care to use them and drive only in accordance with the instructions which come with the drugs. The prescribed defence will only apply where you can show that you have used them in accordance with instructions.

The legal limit for Methamphetamine

The Govt introduced specific legal limits for both illicit and prescribed drugs in March 2015 when the offence of driving above the specified limit for drugs was introduced.

The specified limit for Methamphetamine is 10ug. This is a measurement that is 10,000 fold lower than the analysis for alcohol and the analysis is not subject to the type approval or a presumption that the result is correct. This leads to greater uncertainty in results.

The government did not accept the recommended levels which were set in the Wolff report. The report recommended that the level for Methamphetamine should be 200ug at which they determined a driver would be impaired.*2

Defences for driving over the legal limit for methamphetamine

Laboratories have struggled to effectively analyse blood samples. There have been two laboratories recently which have lost their accreditation due to errors in their analysis of blood samples. Approximately 4,000 cases have been re-opened and convictions set aside as a result.

It is not a perfect science and you cannot assume that the prosecution analysis is 100% accurate it isn’t.

In recent cases we have experienced issues in blood analyses for cocaine and BZE with one toxicologist pointing out the levels of cocaine and BZE were inconsistent with each other and in order to present these corresponding levels our client would have to have been dead, which fortunately he wasn’t. In fact it was an example of cross contamination at the laboratory.

What to look for?

There a number of tell tale signs in the analytical data pack (ADP) which would indicate the result are unreliable.

• Has the laboratory deducted the allowance from the result – this is the allowed margin of error. If not then your result may be below the specified level.
• Does the laboratory have the proper accreditation which is the validation process which examines their processes to ensure their accuracy in analysing blood samples.
• Poor labelling and lack of continuity. All vials must be labelled correctly and followed through the analysis sometimes this gets muddled up and the prosecution cannot prove that the sample tested was the defendants.
• Has the data input been accurate if there is a “data anomaly” it will usually lead to inaccurate results.
• Failings in the quality control sample – each batch of samples must have a control sample to be measured against if this is contaminated in any way the whole batch would usually need to be re-tested but usually isn’t. Such contamination would lead to higher results and render the results unreliable.
• Have they calibrated the results and equipment accurately. The laboratories must test and calibrate their analytical instruments daily. These results must fall within a recommendation range or standard deviation. These are resulted in the form of graphs on the ADP which can be examined and the deviation checked to see if they fall within the recommended range if not the batch should have been re-tested because the results will not be reliable. Laboratories seldom re-test because it is not profitable to do so their margins for profit are so small.
  

Procedural Issues

The prosecution must follows the procedure to the letter, there include:

1. Compliance with S15 Road Traffic Offenders Act 1988 which specifies how blood samples should be taken and what should be done with them after.
   https://roadtrafficdefencelawyers.co.uk/2023/03/14/the-importance-of-keeping-your-blood-sample-taken-by-the-police/
2. Lack of continuity of the sample. The police must be able to show that the sample tested was your sample and failure to label correctly can break the continuity and offer a defence.
3. Failure to disclose evidence which will assist the us as the defence or undermine the prosecution case. The prosecution often fail to serve evidence within a specified period of time and this can lead to arguments to exclude vital prosecution evidence such as the expert report.
   

Post Driving Consumption

Many drivers say that when the police are indicating them to stop driving, they panic because they are in possession of some cannabis so having stopped their vehicle and before the police reach them they eat the cocaine.

This is a defence but we would have to prove this on a balance of probabilities. We would have to show that but for the cocaine eaten you would have been under the limit. If done successfully you would be found not guilty and your case would be dismissed.

The police may have body worn video evidence which will either show that you may have taken cocaine or had the time to take cocaine. Equally it may also show that it was impossible for you to take the methamphetamine.

You will usually need expert evidence to show that but for the cocaine taken after driving you would not have been over the limit.

If you have taken drugs after being stopped then you should tell the police. It makes the argument of post driving consumption more believable.

Special reasons and cocaine

Special reasons can be argued where you have unwittingly taken cannabis in order to avoid the mandatory minimum 12 months ban.

• Medication containing methamphetamine - some medications may contain amphetamine/methamphetamine and this can be examined by one of our experts. It may also be applicable if you had surgery recently. Remember unless prescribed this will not be a statutory defence. You would have had to be unaware that you had taken cocaine.
• Laced drinks - usually you would have get the lacer to give evidence or provide some evidence to show that your drinks were laced. You would also have to produce expert evidence to show that but for the lacing element you would have been under the limit. This is easier to establish if you do not use drugs at all.
  

Reference

1. Symptoms and Signs of Substance Misuse 3rd edition Margaret Stark, Jason Payne-Jamesm Michael Scott-Ham
2. Wolff Report 2013