MLAB 2401: CLINICAL
CHEMISTRY
KERI BROPHY-MARTINEZ
Agents of Toxicology
ALCOHOL

Symptoms

Disorientation, slurred
speech, confusion,
euphoria, paralysis
CNS depressant
 Metabolizes to acetic
acid

After a few drinks…
ALCOHOL CLASSES

Ethanol

Liver most effected
Chronic exposure leads to toxic hepatitis and
cirrhosis
GGT, AST, HDL, MCV all increased with abuse

Found in homemade liquor and commercial products

Rubbing alcohol

Antifreeze and hydraulic fluid
Causes metabolic acidosis and renal tubular damage
Sweet taste attracts children





Methanol
Isopropanol
Ethylene Glycol


DETERMINATION OF ALCOHOLS

Specimen
Serum, plasma, whole
blood
 Avoid use of alcohol in
preparation of site
 Keep sample capped
 Legal alcohol, chain of
custody

MEASUREMENT OF ALCOHOL

Methods
 Enzymatic
 GC: reference method
 Osmometry
CARBON MONOXIDE
Produced by an incomplete combustion of carbon
containing substances
 Colorless, odorless, tasteless gas


Sources
Gasoline engines
 Wood/plastic fires
 Improperly ventilated furnaces

CARBON MONOXIDE

Actions
Binds tightly to hemoglobin and does not allow O2 to
attach to hgb, forming carboxyhemoglobin
 Decreases O2 delivery to the tissues= HYPOXIA


Specimen Type


Whole blood
Methods
GC: reference method
 Differential spectrophotometry

CYANIDE
Component of insecticides and rodenticides
 Common suicide agent


Action


Binds heme iron and prevents the cells from using
oxygen
Measured by ISE
METALS

Arsenic
 Found in the environment
 Binds to proteins to change their structure and function
 Affects cellular and organ systems
Mercury
 Contaminated foods major source of outbreaks
 Protein binding to change the structure or function,
especially enzymes
 Measured by AAS

Cadmium

Found in mining and industrial processes
 Binds to proteins to change their structure and function
Lead
 Review previous lecture notes from Chemistry and
Hematology


THERAPEUTIC DRUGS

Salicylates (NSAID)

Aspirin




Decreases thromboxane and prostaglandin formation
through inhibition of cyclooxygenase which interferes with
platelet aggregation
Interferes with GI function
Overdoses associated with:
 Acidosis
 Formation of ketones due to fatty acid metabolism
 Hyperventilation due to stimulation of respiratory system
Methods
 GC
 Immunoassay
THERAPEUTIC DRUGS

Acetaminophen (NSAID)

Overdose causes

Hepatotoxicity

Tylenol is the brand name

Methods
HPLC
 Immunoassay

DRUGS OF ABUSE: URINE



Qualitative screening
 Uses urine
Problems
 Only detects recent drug use
 Detects drug metabolites
 Detects drug classes
 A positive result can not
discriminate between a single
and chronic use
Overdose can occur with
prescription, OTC or illicit drugs
DRUGS OF ABUSE: URINE

Important to detect specimen adulteration

How can we tell an altered specimen?
Urinary pH
 Specific gravity
 Creatinine


Chain of custody

Important to monitor specimen collection
DRUGS OF ABUSE

Methods

Two-Tiered

Screening
 Simple and rapid spot test

Immunoassay (Ab-Ag Rxn.)
Good sensitivity, marginal specificity
 Detects the class of drugs
 Confirmation
 High sensitivity and specificity
 GC reference method
 Immunoassay methods also used

DRUGS OF ABUSE

Amphetamines

Stimulant used to treat
narcolepsy and attention
deficit disorder

Related compounds




Ephedrine
Pseudoephedrine
“Ecstasy”/ MDMA
Overdose symptoms



Hypertension
Convulsions
Cardiac arrthymia
DRUGS OF ABUSE

Anabolic steroids
 Effect muscle mass; improves athletic
performance

Chronic use causes
 Toxic hepatitis
 Atherosclerosis
 Abnormal platelet aggregation
 Heart enlargement
DRUGS OF ABUSE

Cannabinoids
THC
Tetrahydrocannabinol
most potent
 Psychoactive
compounds

Often used in cancer
treatment regimens
 Half-life

1 day after single use
 3-5 days after chronic
use

DRUGS OF ABUSE

Cocaine

CNS stimulator and local anesthetic
Dose and route of administration
important factor in serum
concentration

Half life




Overdose symptoms


0.5-1 hour
Primary metabolite is benzolecgonine
Hypertension, arrhythmia, seizure, MI
Detection


Urine: up to 3 days post single use
Urine: 20 days post for chronic users
DRUGS OF ABUSE

Opiates
Derived from opium poppy
 Includes opium, heroin,
morphine, codeine,
Dilaudid, Percodan,
Demerol, methodone,
Darvon


Overdose symptoms
Respiratory acidosis
 Myoglobinura
 Cardiac damage

DRUGS OF ABUSE

Phencyclidine or PCP
 Stimulant, depressant, anesthetic and
hallucinogen

Overdose symptoms
 Stupor, coma

Detection
 Chronic users: 7-30 days post use
DRUGS OF ABUSE

Sedatives/ Hypnotics
 CNS depressants

Types
 Barbituates
 phenobarbital, secobarbital
 Benzodiazepines
 Valium, Ativan

Overdose symptoms
 Slurred speech, lethargy, coma
“DESIGNER” DRUGS

Bath Salts- “Vanilla Sky”
 Produce
stimulant/hallucinogenic
effects
 Euphoria
 Increased sex drive
 Can be swallow, inhaled, or
injected
 Can result in life-threatening
effects
 Mimics cathinone
 Found in khat plant
“DESIGNER” DRUGS

Krokodil
Synthetic form of desomorphine
 Similar to heroin highs
 Named for the effect it has on skin

o
Salvia
o
o
o
“Magic mint”
Salvinorin A is the active ingredient
Produces hallucinogenic effects
DESIGNER” DRUGS

Synthetic Cannabinoids
“Spice” or K2
 Produce euphoria
 Difficult to detect

REFERENCES






Bishop, M., Fody, E., & Schoeff, l. (2010). Clinical Chemistry: Techniques,
principles, Correlations. Baltimore: Wolters Kluwer Lippincott Williams
& Wilkins.
Eden, M. P. R. (2014, March). An overview: drugs-of-abuse testing in the
clinical laboratory today. MLO, 46(3), 22-24.
Crews, B. O. (2013, February). Synthetic cannabinoids. Clinical
Laboratory News, 39(2), 8-10.
http://www.alcoholrehabsandiego.com/drug-tests/
http://www.becksgf.com/index.php?main_page=product_info&cPath=9_10
6&products_id=71
http://www.canadianhempco.com/index.php?main_page=product_info&cP
ath=4_69&products_id=618

http://daly-tribe.com/Humor/Alcohol_effects.htm

http://www.healtylifeblog.com/2009/11/anabolic-steroids-in-sports/
REFERENCES

http://www.prostatespecificantigen.net/products.htm

http://signsofcocaineuse.com/

http://vyssute.com/downloads/demotivational/

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

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McDaniel, G. (2014, January). Drus of Abuse Testing: Old & New.
Advance for Administrators of the Laboratory , 23(1), 24-27.
Moran, J., & Seely, K. (2014, March). Bath Salts. Clinical
Laboratory News, 40(3), 8-10.
Neuroscience for Kids- Bath Salts. (1996-2012). Retrieved from
https://faculty.washington.edu/chudler/salts.html
Sunheimer, R., & Graves, L. (2010). Clinical Laboratory
Chemistry. Upper Saddle River: Pearson.
Wikipedia. (2014). Retrieved from
http://en.wikipedia.org/wiki/Synthetic_cannabis