ChemPath: Drug, Forensics and Toxicology

Question 1

What sorts of deaths are reported to the coroner?

Answer 1

1. Violent
2. Unnatural or sudden
3. Cause of death is unknown

A number of these require analysis for drugs and alcohol in order to establish the cause of death

Question 2

What sorts of case types are reported to the coroner?

Answer 2

• Addicts / drug use
• Sudden unexplained / natural
• Hanging
• Overdoses
• Road Traffic Collisions
• Train deaths
• Self-inflicted injury
• Fire

Question 3

What samples do coroners take?

Answer 3

• Ante-mortem serum / blood
• Post-mortem blood
• Heart blood, cavity blood (screening)
• Femoral vein blood (screening and quantitation)
• Urine
• Stomach contents
• Vitreous humor
• Hair
• Liver
• Others – bile, muscle, powders, syringes

Question 4

What is the most common drug problem?

Answer 4

Alcohol

Question 5

What are the main problems associated with alcohol?

Answer 5

• OD
• Accidents including RTCs
• Additive effects other respiratory depressant drugs

Question 6

What are the main problems associated with heroine?

Answer 6

• IV injection, volatilised
• Fatal OD with both routes of ingestion
• Additive effects other respiratory depressant drugs
• Few rapid deaths
• Most respiratory depression or aspiration pneumonitis
• Tolerance

Question 7

What is toxicology?

Answer 7

Concerned with anaylsing samples of drugs/poisins and interpreting the significance of the results.

Question 8

What does ‘forensic’ mean?

Answer 8

Results/reports used in court

Question 9

Why might drug levels appear erroneoously elevated post-mortem?

Answer 9

Tissue breakdwon can lead to the release of drugs from various tissues

Question 10

Where can a sample be taken from for drug concentration measurement?

Answer 10

Femoral vein blood

Question 11

When is vitreous humour used as a sample?

Answer 11

Used to measure glucose (may be elevated in DKA)

Question 12

How can heroin overdose kill?

Answer 12

Respiratory depression or aspiration pneumonitis

Question 13

What are the acute dangers of cocaine?

Answer 13

• Cardiac dysrhythmias
• Acute heart failure
• MI

Question 14

What is the effectof mixing ethanol with cocaine?

Answer 14

Forms cocaethylene which prolongs the effects of cocaine

Question 15

What happes to cocaine in post-mortem blood?

Answer 15

Breaks down rapidly so the concentration in post-mortem blood may be considerable lower than at the time of death.

Question 16

Describe the consequences of amphetamine overdose.

Answer 16

Causes hyperthermia → rhabdomyolysis → renal failure

Also has a direct toxic effect on the heart

Question 17

List some examples of legal highs.

Answer 17

• Stimulats (e.g. bath salts)
• Synthetic cannabinoids
• Synthetic opioids (e.g. acetylfentanyl)
• Hallucinogenic compounds

Question 18

How long can drugs be detected for in the:

1. Blood and serum
2. Urine

Answer 18

1. Blood and serum = 12 hours
2. Urine = 2-3 days

Question 19

How are hair samples used in forensic toxicology?

Answer 19

• Demonstrating a history of drug use or lack of it
• Demonstrating tolerance or lack of tolerance to drugs (helps interpret post-mortem drug concentrations)
• Compliance with medications (e.g. antipsychotics)

NOTE: hair samples are rarely used in coroner’s toxicology but it is used in forensic investigations

Question 20

What are the issues with hair analysis?

Answer 20

• Environmental contamination
• Absorbed from sweat or sebum coating the hair
• Passive inhalation
• Cosmetic treatment (e.g. shampoo)
• Hair colour

Question 21

What are the two causes of death due to cocaine use?

Answer 21

• Depression/suicide due to long term cocaine use
• Sudden unexplained death

Question 22

What are the main drugs used in chemsex?

Answer 22

GHB

Methylamphetamine (crystal meth)

Mephedrone

Question 23

How is Alcohol assessed in toxicology?

Answer 23

GC-MS for analysis of volatile compounds?

Question 24

How are drug screens done?

Answer 24

Gas Chromatography Mass Spec of urine

Question 25

How are morphine, cannabus and amphetamines screened for?

Answer 25

• • Morphine → Enzyme Immunoassay (EIA)
  • Cannabis → GC-MS
  • Amphetamines → GC-MS

Question 26

Why are immunoassays not used in toxicology?

Answer 26

High false positive and negative samples

Question 27

Fatality of methadone?

Answer 27

Slow death (4-6 hours) -> 5ml for kid 60ml for adult.
Addative effect with other respiratory depressants

Question 28

Fatality of Benzos ?

Answer 28

• Extremely rare to cause death alone
• Additive effects with other respiratory depressant drugs (e.g. morphine)
  
  • Taken when experiencing the comedown from morphine

Question 29

Fatality of Cannabis ?

Answer 29

• Never fatal alone
• Found in RTAs (driving after alcohol + cannabis, lethal combination)

Question 30

SpeedBall

Answer 30

Cocaine + Heroin -> immediate high then maintained

Question 31

Amphetamine and Stimulants - fatality?

Answer 31

• Large OD causes direct toxic effect on heart
• Can cause hyperthermia → rhabdomyolysis →muscle necrosis and renal failure

Question 32

Fatality of Pregabalin and gabapentin?

Answer 32

• Prescribed for epilepsy and neuropathic pain - often alongside other analgesics (e.g. Codeine)
• Used by drug users for euphoria (similar to that from heroin) – Class C drug

Question 33

Spice?

Answer 33

• HU-210 is similar to Δ9THC (similar structure and activity, additional group added to slightly modify it)
  
  • Synthesised in clandestine labs
  • Impregnated herbal material, smoked
• Very cheap (used by the homeless)
• Lacks the characteristic smell of cannabis (used in Prisons)
• Higher prevalence but severe adverse effects
  
  • Hypertension, tachycardia, hallucinations, agitation, paranoia, seizures, panic attacks