Forensic Toxicology - Drugs and Poisons 101: Information for Writers

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Excerpt WEAKEST LYNX

       I undressed in the bathroom. When I lifted the hamper lid, my peripheral vision caught a dark face reflected in the mirror. I gasped, my brain processing like a camera with an open shutter. Click. Tribal tattoos. Click. Gas mask. Click. Sink on right. Click. White cloth. Click. Sweet odor. Click. No alarm. Click. No help.

       While my mind snapped perceptions, my body acted from training. I lowered my hips to drop my weight for better balance and leverage. My left leg swung behind his. I bent my knee in a swift, sharp move as I reached over my head, grasping his shirt to put him on the floor.

        But the initial fumes I had sucked in made the room watery and undulating, melting my muscles and my instincts into useless puddles. My arms dropped ineffectually to my sides. One of his hands trapped me against him as I dangled, unable to hold my weight up with my legs, while his other hand smashed the cloth tightly over my nose. 

 (Photo credit: Wikipedia)

Forensic Toxicologists study how animals are affected by drugs and poisons. They work for various independent companies as well as agencies.

Inside a forensic department there are typically two chemistry labs housed in different locations because of the potential for cross-contamination. There are:
1 Contraband Substances Labs
* Identifies substances in seized form
* Typically measured in gram and kilograms
2 Toxicology Lab
* Identifies substances that are found in urine, blood, and tissues
* Typically measured in micro-gram and nano-grams
What is a Forensic Toxicologist (1:50)

Some Useful Vocabulary:
A drug - single chemical or compound chemical that has psychological and or physical reactions on the

(Photo credit: Wikipedia)

   body.
* Prescription
* Over the counter
* Recreational
   legal - such as alcohol
   illegal - such as heroine
* Natural - such as caffeine

A poison has life threatening 
                effects.
Toxicology - The study of how humans and animals are
                affected by poisons or drugs
Forensic Toxicology - how the affect of drugs and
                 poisons have legal ramifications
Synergism - Forensic Toxicologist must be mindful
                  of Synergism - When two or more drugs or
                  substances work together to increase the effect such as
                  alcohol and barbiturates. Jimmy Hendricks, Janice
                  Joplin are two examples.
Pharmacologyy - the science of understanding the way drugs act
                  and the affects they have on a body
Pharmoketetics study of how drugs move - including how they get
                  into and out of the body
Absorption - how a drug gets into a body 
                        VIDEO QUICK STUDY Absorption and Dose (7:49)

 1. The drug can be inserted intravenously - shot directly into a
      vein/ the blood system. They can also be shot into a muscle 
      where they will enter the blood in a gradual manner.
 2. Orally - entering the body through the digestive tract
 3. Rectal insertion - crossing the mucus lining into the gastro-
     intenstinal tract
 4. Inhaled - such as for asthmatics or with a nebulizer or gas like
     carbon monoxide poisoning.
 5. Deramal - lotions and other products that are applied to the skin,
     but will not typically show up in significant quantities in the
     blood stream.
 6. Ocular

Distribution - almost always the product is distributed to the rest
     of the body through the blood/circulatory system. These do not
     circulate in an even way.
 1. The heart and liver - often have a higher concentration
 2. The brain - many drugs cannot get into the brain because blood
     networks in the brain are less permeable than other parts of the 
     body.
 3. Some products simply build up in the system. Pesticides, for
     example, build up in fatty tissues (adipose) over time. 
     Example of this is mercury in fish.

Metabolism - (broken down into metabolites) usually happens in
      the liver.
 1. Drug is deactivated with time.
 2. Body eliminates the drug
 3. Converts it into a substance that can be used for energy

Elimination - 
  1. Most is removed through urine (that's why urine testing is so 
      important)
  2. Feces
  3. Sweat
  4. Lactation
  5. Hair follicles. 
      VIDEO QUICK STUDY of hair toxicology (1:10)
  6. Exhalent VIDEO QUICK STUDY - A breathalyzer to analyze
       alcohol consumption (:50)

Poisonings can occur by:

Accident

•   Child poisoning
•   Storing improperly, putting a poison in an incorrect 
•   Container/mislabeling
•   Taking the wrong medication
•   Taking one's medication multiple times during the day (do     to dementia, etc.)

  Adverse drug interactions

•  An individual might have specific issues such as organ    damage that is exacerbated over time by taking certain     medications.
•  Environmental causes such as radon or industrial chemicals
•  Animals such as spiders or snakes
•  Plants

  Overdose on recreational drugs VIDEO QUICK STUDY of street drugs and their forensic effects (9:52)

Suicide only fatal about 2% of the time but often results in organ 
             damage.
Homicide 

An arrangement of psychoactive drugs (Photo credit: Wikipedia)

In a living person signs of poisoning might include:

• nausea and vomiting
• respiratory distress
• change in skin coloration
• seizures
• blurred vision
• slurred speech
• mental confusion
• swelling
• Loss of consciousness

The severity of the reaction depends on many factors including:

•  Size of the victim
•  Health of the victim
•  Amount of substance
•  Duration of exposure

When deciding if this was a suicide or homicide investigators may utilize a forensic psychologist or death investigator to interview family, friends, and coworkers to put together a picture of their health  history, their state of mental health, and their history of drug use both legal and illegal.

Tests can be performed on the living or the dead.
Subjects who are living might be tested for some of these reasons:

•  Pre-employment drug tests
•  Randomized drug testing for public safety
•  Athletes
•  Crime scene - was a suspect under the influence?
•  Victim of a crime - for example was a date rape drug used?

   Blog - How to Drug Your Victim - the Four Main Date Rape Drugs

Post-mortem Forensic Drug Tests are done by Forensic Toxicologist and/or Forensic Pathologist - medical doctors specializing in disease and chemistry.

In trying to determine the poison/toxin there are three main steps:

Sample - Postmortem Sampling List will probably look at:

•       blood
•       urine
•       stomach contents
•       bile and liver (site of metabolism for many drugs)
•       brain tissue/spinal fluid
•       vitreous fluid (from the eye) Even in a body that has                  already started to breakdown, this is often a place where             toxicologists can gather information because the eye is               more resistant than other tissues to decomposition.

(Photo credit: Jack Spades)

•       fatty deposits
•       hair - this is the longest lasting           source of a decomposed body.

Screen -
      * indicates a drug might be present
      * some drugs mimic naturally 
         occurring substance
      * Gas Chromotography VIDEO QUICK STUDY (1:12)
      * Enzyme Multiplied Immunoassay Testing
         VIDEO QUICK STUDY (2:06)
Extract -
     * concentrates the drug so it's easier to detect
     * removes other substances that might contaminate the results
     * Mass Spectometry VIDEO QUICK STUDY (7:59)
       qualitative and quantitative information is gathered

Please let me know if you have any questions, and I will do my best to help.

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