Lecture 8 - Drug testing Flashcards
What are the 2 main matrices for drug testing?
Blood and urine
What are advantages of using urine?
Ease of collection
Ease of testing
High conc of parent drug and metabolites
Sufficient volume size
Cheap
What are the disadvantages of using urine?
May only be present for 1-7 days.
Samples are at risk for tampering.
Have to observe collection of sample to prevent swappages.
What are the advantages of using blood?
Detection of drugs in the body at that time
Can detect drugs and metabolites
Thought to be more precise than urine
Harder to mask illicit substances
What are the disadvantages of using blood?
Sample must be taken by a medically trained individual
Collection of the sample is more costly and
time consuming
The sample must be stored with anti-clotting and anti-bacterial agents to prevent
deterioration of the sample
Temperature of the stored sample must also be carefully controlled
What are the Ad and DisAd of sweat?
Easy to collect in sport
Non-invasive
More likely to detect metabolite than unchanged drug.
Limited research of drug presence.
How can fingerprints be used?
Intelligent fingerprinting developed technique using sweat for fingerprints.
There is a fluorescence system designed to be portable and rapid for on scene testing
A second confirmatory system using LC-MS to confirm the presence of drugs in the fingerprints in a lab setting.
Using fingerprints is a quick and simple method of sample collection
Non-invasive
What are the A/DA of using hair?
Non-invasive
Relatively simple to collect
Large amounts often available
Can give an indication of drug use over a long period of time
Not much research
What are the A/DA of using saliva?
Relatively non-invasive
Variable amounts available
Can be altered by dilution
Can be altered by masking compounds
May have issues with breakdown of compounds this must be considered when storing samples
Further research needed on drugs that can be detected
What are the A/DA of using breath?
Regularly used for detecting alcohol
Relatively non-invasive
Requires instrumentation that must be
correctly calibrated
Further research needed for different drugs
How is workplace testing done?
- Usually urine
- Tests for common abused substances
- Uses ELISA for drug detection
- Quick and simple
- Need to know medical records in case drugs are prescribed
How is drug driving testing done?
- The road traffic act 1988 preliminary testing can be carried out at the roadside – but currently only using sweat or saliva.
- Mobile testing devices are in use with others being developed – focus on cocaine and THC
Drivers can also undergo impairment tests - like walking in a straight line
What is key to developing a drug driving testing technique?
- Portable
- Simple
- Unambiguous results
How is drug testing in sport done?
- Initially done after testing but now done at unknown times called whereabouts.
-Testing of body fluids for the presence of pharmaceutical drugs is undertaken only by laboratories that are World Anti Doping Agency WADA accredited. - Based in London in the UK - uses urine but will use blood if needed.
How do the WADA labs work and become accredited?
An accredited laboratory must be assessed by WADA every 4 months and seek re-accreditation annually.
Initial accreditation requires the successful
analyses of 3 sets of 10 samples over a period of 6 – 12 months. Work must be fully
documented.
An analytical test must also by carried out in the presence of a delegate of the International Olympic Committee (IOC) Sub-Commission on Doping and Biochemistry.
Re-accreditation involves analysis of up to 10 control samples within a specified time limit.
For major sporting events the laboratory
must be able to report on results within 24 – 48 h of receiving the sample.
