7.6 - TOXICOLOGY OF DRUGS OF ABUSE

urine

recent

Toxicology of Drugs of Abuse

Screening: Usually via _; detects _ use

immunoassay

GC-MS, LC-MS

Toxicology of Drugs of Abuse

Methods:

Initial _ (sensitive, less specific)

Confirm with _-_ (reference method) or _-_

pH

temp

SG

creatinine

chain of custody

Toxicology of Drugs of Abuse

Sample Integrity: Check _, _, _, _; _ _ _ vital in medicolegal settings

Amphetamine/Methamphetamine

Uses: ADHD, narcolepsy; high abuse potential

Hypertension

Amphetamine/Methamphetamine

Toxicity: _, arrhythmias, seizures

positives

cold and allergy

Amphetamine/Methamphetamine

Screening consideration: False _ from OTC _ and _ meds such as ephedrine, pseudoephedrine, and phenylpropanolamine

Sedative-Hypnotics (Barbiturates & Benzodiazepines)

Toxicity: CNS depression, respiratory failure; worsened by alcohol

Barbiturates & Benzodiazepines

Sedative-Hypnotics (2)

3, 30

urine

Sedative-Hypnotics (Barbiturates & Benzodiazepines)

Detection:

Barbiturates: Detected for up to _ days (phenobarbital: up to _ days)

Benzodiazepines: Only metabolites seen in _; varies by compound

Cannabinoids (THC/tetrahydrocannabinol)

Effect: Euphoria, cognitive impairment; slow clearance due to fat storage

Urine, THC-COOH

1-5

detection window

Cannabinoids (THC/tetrahydrocannabinol)

Detection: _ detection of _-_ (11-nor-9-carboxy-tetrahydrocannabinol)

Half-life varies, within _-_ days

Note: Chronic use → prolonged _ _

morphine, codeine

heroin, oxycodone

fentanyl, methadone

Opioids

Types: Natural (2), semi-synthetic (2), synthetic (2)

cardiac markers

Naloxone

Opioids

Toxicity: Respiratory acidosis, _ _ ↑ (CK-MB, troponin), death via cardiopulmonary failure

Antidote: _

serotonin and norepinephrine

Tricyclic Antidepressants (TCAs)

Mechanism: Block reabsorption of (2)

suicidal attempts

depression

Tricyclic Antidepressants (TCAs)

Structure: Named for three-ring (tricyclic) structure

Other notes: Often involved in _ _ due to toxicity risk

Use: Treat _ and mood disorders

Imipramine

TRICYCLIC ANTIDEPRESSANTS
Drug	Description
_	Metabolized to Desipramine Toxicity: Ventricular tachycardia at high levels

Amitriptyline

TRICYCLIC ANTIDEPRESSANTS
Drug	Description
_	Metabolized to Nortriptyline Toxicity: Ventricular tachycardia above 500 ng/mL

Doxepin

TRICYCLIC ANTIDEPRESSANTS
Drug	Description
_	Metabolized to Nordoxepin Toxicity: Cardiac dysrhythmias above 500 ng/mL

Methylenedioxymethamphetamine (MDMA/Ecstasy)

Type: Illicit amphetamine derivative; “designer drug”

oral, 50-150

Euphoria

Methylenedioxymethamphetamine (MDMA/Ecstasy)

Administration: Mostly _ (tablets _-_ mg); also, inhalation, injection, smoking

Desired effects: _, hallucination, empathy, enhanced sensory perception

8-9

hepatic, urine

Methylenedioxymethamphetamine (MDMA/Ecstasy)

Half-life: Approx. _-_ hours

Metabolism: Primarily _; ~20% excreted unchanged in _

30-60

~3.5

Methylenedioxymethamphetamine (MDMA/Ecstasy)

Onset & Duration: Onset: _-_ mins | Duration: _ hours

Neurologic

Cardiovascular

Systemic

Methylenedioxymethamphetamine (MDMA/Ecstasy)

Adverse effects:

_: Anxiety, agitation, memory loss, seizures

_: Tachycardia, hypertension, cardiac toxicity

_: Hyperthermia, respiratory depression, liver and renal failure

urine immunoassays

Methylenedioxymethamphetamine (MDMA/Ecstasy)

Note: Routine _ _ often fail to detect MDMA

Phencyclidine (PCP/Angel Dust)

Type: Illicit drug with stimulant, depressant, anesthetic, and hallucinogenic properties

Agitation

Oral ingestion, inhalation

Phencyclidine (PCP/Angel Dust)

Adverse effects: _, paranoia, hostility, stupor, coma (in overdose)

Routes: _ _ or _ (e.g., PCP-laced tobacco/marijuana)

Lipophilic

Slow

10-15, 30

Phencyclidine (PCP/Angel Dust)

Pharmacokinetics:

_ → distributes rapidly to fat/brain

_ elimination due to redistribution and metabolism

_-_% excreted unchanged in urine (detectable for up to _ days in chronic users)

Anabolic Steroids

Type: Synthetic compounds related to testosterone, variable quality/purity

male hypogonadism

Anabolic Steroids

Uses: Originally for _ _; now commonly abused to enhance muscle mass and athletic performance

Prevalence: 6.5% of adolescent boys and 1.9% of girls use without prescription

illicit

Anabolic Steroids

Sources: Mostly _—black market or foreign sources

Acute

Chronic

Males

Females

Anabolic Steroids

Toxic Effects:

_: Due to high dosages and impurities

_: Hepatic: Cardiovascular

_: Testicular atrophy, sterility, impotence

_: Masculinization, breast reduction, sterility

Testosterone:epitestosterone ratio

exogenous

Anabolic Steroids

Common detection method: _:_ _ (↑ ratio suggests _ use)