Psychoactive Drugs

TOXICITY The study of poisons & the identification of drugs & other substances a person may have used for medicinal, recreational, or criminal purposes. The study of poisons & the identification of drugs & other substances a person may have used for medicinal, recreational, or criminal purposes.

TOXICITY The degree to which a substance is harmful The degree to which a substance is harmful Depends on: Dose: how much has been taken Dose: how much has been taken Duration: frequency and length of exposure Duration: frequency and length of exposure Type of Exposure: how was the drug taken Type of Exposure: how was the drug taken –Inhalation –Ingestion –Absorbed –Injected Drug Interactions Drug Interactions –Additive –Antagonistic –Synergistic

Looking for Toxins Most don’t cause visible changes in body Most don’t cause visible changes in body Collect fluids and/or tissues to analyze Collect fluids and/or tissues to analyze –Test for actual substance or metabolites Heroin converted to morphine Heroin converted to morphine Collecting Samples Collecting Samples –From points of entry (stomach) –Where they concentrate (blood, liver) –Routes of elimination (urine)

Collecting Samples con’t. Skin, hair Skin, hair Urine: easily sampled, poor correlation Urine: easily sampled, poor correlation Blood: good correlation w/ intoxication Blood: good correlation w/ intoxication Stomach: poor correlation w/ blood levels Stomach: poor correlation w/ blood levels Liver: heavy metals, provides timeline Liver: heavy metals, provides timeline Insects: helpful with severe decompostion. Insects: helpful with severe decompostion. Vitreous Humor: resistant to decay Vitreous Humor: resistant to decay

Did You Know? Saliva-based drug tests are as accurate as urine-based tests. The saliva test can generally detect illegal drugs immediately on use for up to about 72 hours.

Alcohol Alcohol Absorbed rapidly Absorbed rapidly Full Absorption: Full Absorption: –within 30 minutes of last drink –90 minutes with food in stomach Metabolism Metabolism –90-98% by liver  CO 2 + H 2 O BAC ^ if absorption > elimination BAC ^ if absorption > elimination –Average drinker:.015g/ml/hr –Alcoholic:.030g/ml/hr –Non-drinker:.005g/ml/hr

Levels of impairment at different BACs

BAC con’t. BAC = fluid ounces of beverage x % alcohol BAC = fluid ounces of beverage x % alcohol body weight X (r) r = 13.1 for males r = 10.6 for females Example: 155 lb. male had 4 beers (12oz., 4%) BAC = (48)(4) / (155)(13.1) = 0.095g/100ml Maryland DWI.08 ; Colorado DWAI: 0.02

BAC Problem 155lb male 155lb male BAC = 0.12g/100ml BAC = 0.12g/100ml “I only had a beer or two.” How many beers? (assume 4% alcohol) How many beers? (assume 4% alcohol) BAC = fluid ounces of beverage x % alcohol body weight X (r) 0.12 = (# of oz.)(4) / (155)(13.1) # of oz. = 60.9 (5.07 beers)

BAC Extrapolation 2:00am 2:00am Driver stopped 11:30pm Driver stopped 11:30pm Blood test results:. Blood test results:. 5:00am Elimination rate = ( )/1 hr. =.01/hr Elimination rate = ( )/1 hr. =.01/hr 2:00am =.16 + (2hr)(.01/hr) 2:00am =.16 + (2hr)(.01/hr) =.18g/100ml

Did You Know? If two people use the exact same amount of a drug & are tested, the person with darker hair will retain more drug in his or her hair than the lighter-haired person.

DWI Field Test

Meth Users

Brain on Cocaine

Normal Spider Drugs and Spiders

Caffeine

Marijuana

LSD

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