forensics lecture 3- drugs Flashcards
what is pharmacodynamics?
The study of the dose versus pharmacological response
what is pharmacokinetics?
The study of the ADME processes over a period of time
Absorption, Distribution, Metabolism & Elimination
what is pharmacogenetics?
The study of genetic influences/variances on the ADME processes
what is forensic toxicology?
Study of the effects of alcohol, drugs or poisons with application to the law.
-Post-mortem toxicology
-Human performance
-Drug testing (workplace/sports)
what are the types of toxicology cases?
-Road Traffic Act offences
-Drink driving
-Drug driving
-Drug-facilitated sexual assault
-Hair testing for social services
-Sudden or suspicious deaths
what is paracelsus’ third defence?
Dosis facit venenum
-“What is there that is not poison?
All things are poison and nothing without poison.
Solely the dose determines that a thing is not poison.”
what are types of class A drugs>
-Major natural and synthetic opiates
-cocaine and crack cocaine
-LSD
-injectable amphetamines
-Cannabinol
-Magic mushrooms
-Ecstasy
what are types of class B drugs?
-Oral Amphetamines
-Cannabis plant material and resin
-Codeine, Dihydrocodeine
-Certain barbiturates
what are types of class C drugs?
-Benzodiazepines
-Methaqualone
-Gamma Hydroxybutyrate (GHB)
-Ketamine
what information can we get from the analysis of drugs?
-Qualitative/quantitative
-Bulk/Trace
-Chronic/Acute
-Screening
-Confirmation
-Targeted analyses
what are the methods of analysis of drugs?
-Presumptive tests
-Thin Layer Chromatography
-Column Chromatography
-HPLC
-Gas Chromatography
-Mass Spectrometry
-Immunoassay
-Spectroscopy
how do we use hair to analyse drug use?
-Drugs bind to melanin – weak bases
-Heat/volatise to smoke (Uncharged/free base) – nicotine, cocaine, heroin
-Hair grows 0.35mm/day 1cm/month
-Metabolites can also be detected – this identifies drugs coming from the body.
how does workplace drug testing occur?
Core drug groups: Cannabis, Cocaine, Amphetamines, Opiates
Testing: Saliva, Urine, Hair
what is amphetamines and its effects?
Methamphetamine – stimulant
Administration: Inhalation, oral, snorting, injection
Action: Increased dopamine
Effects:
-increased wakefulness and physical activity
-decreased appetite
-faster breathing
-rapid and/or irregular heartbeat
-increased blood pressure and body temperature
Long term effects:
-HIV/AIDS
-Weight loss
-Severe dental problems (“Meth mouth”)
what is ecstasy and what are the effects of the drug?
Ecstasy (Molly and MDMA)
Chemically similar to stimulants/hallucinogens
Increase in activity of:
Dopamine – Euphoria & increased energy/activity
Norephinephrine – Increased heart rate & blood pressure
Other effects: nausea, muscle cramping, blurred vision
Effects last 3-6 hours
High doses affect temperature regulation
Psychotherapy?
what is cocaine and what are the effects of the drug?
Extraction from cocoa leaf/ chemical synthesis
Administration : SNORTING, injection, oral
Stimulant: Increases levels of dopamine
Short-term health effects of cocaine include: extreme happiness and energy , mental alertness, hypersensitivity to sight, sound, and touch , irritability, paranoia
Other health effects of cocaine use include: constricted blood vessels , dilated pupils, nausea, raised body temperature and blood pressure, faster heartbeat, tremors and muscle twitches, restlessness
what is heroin and what are the effects of the drug?
Active ingredients :Diamorphine, other opiates e.g. codeine
Names: Smack, horse, brown
Administration: Smoking (chasing the dragon), IV
Legislation: Class A
Effects:
Analgesia, Dreamy euphoria, Sedation, Respiratory depression Nausea and vomiting, Cough suppression, Constipation
what are LSD (Lysergic Acid Diethylamide) and what are the effects of the drug?
Hallucinogen synthesised from Lysergic acid
Microdots/ blotter acids
Dosage 50 -300mg (20-25mg sufficient)
Affects the actions of brain chemical glutamate (NMDA receptors) /seretonin
Rapid emotional swings; distortion of a person’s ability to recognize reality, think rationally, or communicate with others; raised blood pressure, heart rate, body temperature; dizziness and insomnia; loss of appetite; dry mouth; sweating; numbness; weakness; tremors; enlarged pupils.
what is cannabis and what are the effects of the drug?
Names: Pot, weed, hash, grass, dope
Administration: Smoking, dabbing, food
Legislation: Depends on preparation
- Cannabis plant and resin (Class B), oil (Class A)
Effects: Euphoria, Nausea, Hypotension, Bloodshot eyes, Poor coordination, distortion, Munchies
Speed depends on method of administration (smoking = minutes, oral ~ 1 hour)
what are benzodiazepines?
Prescription drugs
Street names: Moggies, jellies
Administration: Oral, injection
Actions: Depressants – reduce tension and anxiety, drowsiness
Flunitrazepam – “date rape”
what do drugs cause?
-Fatal Poisoning
-suicide
-accident
-industrial
-homicide
-iatrogenic
what are the 5 factors affecting toxicity?
Dose Response curve: LD50 – ½ Maximum response
Sensitisation: Second time may have enhanced immune response
Tolerance: When repeatedly exposed
Accumulation: Long half-life
Bioavailability: Proportion of original dose absorbed and rate absorption takes place
