forensics Flashcards
alcohol and drug toxicology
the definition of pharmacodynamics and pharmacokinetics ?
dynamics= what the drug does the the body systems
kinetics= what the body does to the drug, refers to the absorption, distribution, metabolism and elimination of drug in the body.
describe the absorption, distribution, metabolism and elimination of alcohol in the body?
absorption- factors affecting the rate of absorbiton= quantity, food, time in GI tract.
distribution- distribution of alcohol to all organs and body compartmnets in proportion to the body compartments water content. as they are equilibrium with blood.
metabolism- >90% of alcohol is metabolised by the body
elimination- the rest 10% is excreted eg urine.
as the liver converts ethanol - acetaldehyde to get waste products c02 and water.
describe how to interpret blood alcohol levels in terms of mg/100ml
under 50= not obvious
50-100- slurred speech
400+= death
the body reduced blood alcohol concentration by 15mg/ 100ml - 18mg/100ml per hour.
testing blood alcohol is the most accurate way to test alcohol concentration
what is the main enzyme/ influence involved in alcohol metabolism?
ADH
why people metabolise alcohol differently? (KM reading)
genetics- different people have different ADH.
km= more active the enzyme the quicker alcohol is metabolised
the legal limit of alcohol in blood in England and Scotland ?
England - 80mg/ 100ml
scotland - 50mg/100ml
examples of chemical analysis of alcohol (which is not accurate enough to convict someone)
1) electrochemical fuel cell breathalyser
2) infrared optical sensor breathalyser
the rate of which slow, fast and average metabolisms metabolise alcohol?
slow- 9mg/100ml
fast- 27mg/100ml
average- 18mg/100ml
range= fast-slow
describe the 3 classes of the ‘misuse of drugs 1971 act’
class A- most dangerous drugs eg cocaine, herioin.
class B- less harmful but still illegal eg cannabis
class C- carry legal restrictions eg anabolic steroids
3 ways to analyse drugs?
1) gas chromatography- vaporises substance to identify dugs eg cocaine, herioin
2) thin layer chromatography- separates and identifies small amount of substance on a TLC plate.
3) can identify long term drug use as drugs bind to melanin.
