TOXIC AGENTS Flashcards
- Single, short term exposure
Acute toxicity
- Repeated exposure for extended periods
Chronic toxicity
- rate at w/c the substance can reach the circulation
Routes of exposure
– movement of substance
Passive diffusion
ALCOHOLS AND GLYCOLS
• Ethanol
• Methanol
• Ethylene glycol
• Isopropyl aldohol
Fatal dose of 100% pure ethanol: [?] of pure ethanol consumed in less than an hour
300-400 ml
Varied effects of serum levels on human function
ETHANOL
1-2
10-50 mg/dl
None to mild euphoria
10-50 mg/dl
3-4
50-100 mg/dl
100 mg/dl
Mild influence on stereoscopic vision and dark adaptation
50-100 mg/dl
Legally intoxicated
100 mg/dl
4-6
100-150 mg/dl
Euphoria; disappearance of inhibition; prolonged reaction time
100-150 mg/dl
6-7
150-200 mg/dL
Moderately severe poisoning
150-200 mg/dL
reaction time greatly prolonged
150-200 mg/dL
loss of inhibition and slight disturbances in equilibrium and coordination
150-200 mg/dL
8-9
200-250 mg/dL
Severe degree of poisoning
200-250 mg/dL
disturbances of equilibrium and coordination
200-250 mg/dL
retardation of thought processes and clouding of consciousness
200-250 mg/dL
10-15
250-400 mg/dL
Deep, possibly fatal coma
250-400 mg/dL
Serum concentration: Enzymatic, GC or Electrochemical Oxidation
(direct determination)
ETHANOL
• Serum(ethanol) - NAD→[alcohol DH] →
acetaldehyde + NADH
• 340 nm absorbance : direct determination of alcohol present
ETHANOL
- simplest aliphatic alcohol comprising of methyl and alcohol group
METHANOL
METHANOL
- Method of choice:
GC-MS
METHANOL
- Treatment: (principle: competition)
ethanol therapy
•Wood alcohol
METHANOL
•Ingestion of methylated spirits or methanol-containing antifreeze
METHANOL
• Rapidly absorbed from the GIT
METHANOL
METHANOL
• Toxic dose:
60-250 ml
• [?] → formaldehyde → formic acid (toxic)
METHANOL
• Ocular toxicity and metabolic acidosis
METHANOL
ETHYLENE GLYCOL
- Fatal dose:
100 g
ETHYLENE GLYCOL
- Method of choice:
HPLC
ETHYLENE GLYCOL
- Treatment:
ethanol therapy
ETHYLENE GLYCOL
- Principle:
competition
1,2-ethanediol
ETHYLENE GLYCOL
ETHYLENE GLYCOL 3 toxic metabolites:
- Glycoaldehyde
- Glycolic acid
- Glyoxylic acid
Metabolized into acetone, CO, & H2O
ISOPROPYL ALCOHOL
ISOPROPYL ALCOHOL
Fatal dose:
250 ml
Clues to diagnosis: acetonuria, acetonemia, hyperosmolarity without hyperglycemia or acidosis
ISOPROPYL ALCOHOL
- Rubbing alcohol
ISOPROPYL ALCOHOL
ISOPROPYL ALCOHOL
- Method of choice:
Gas Chromatography
ISOPROPYL ALCOHOL
- Treatment:
ethanol therapy
Binds to hemoglobin to form CARBOXYHEMOGLOBIN (cherryred)
CARBON MONOXIDE
Tissue hypoxia, respiratory, neurologic and cardiac symptoms
CARBON MONOXIDE
CARBON MONOXIDE
-Key symptom:
Dyspnea (labored breathing)
CARBON MONOXIDE
- Treatment:
100% oxygen theraphy
Binds to ferric ion
CYANIDE
: inactivates iron-containing enzymes
Cyanoferric complex
Binds to Cytochrome oxidase
CYANIDE
(inhibits ETC and prevents cellular respiration)
Cytochrome oxidase
- Key symptom: tachypnia: resporatory depression + cyanosis + hypotension, convulsion, coma (death in a few minutes)
CYANIDE
- Clues to diagnosis : odor of bitter almonds
CYANIDE
Rodenticides, weed killers, insecticides
ARSENIC
Interacts w/enzyme SH groups → disrupts multiple metabolic systems
ARSENIC
ARSENIC Acute fatal dose:
120 mg
- Key symptom: GIT symptoms
ARSENIC
- Analysis: gastric lavage; urine samples
ARSENIC
ARSENIC
- Treatment:
emesis/hemodialysis
VI. METALS
Acute poisoning common in young children
IRON
IRON Toxic amount:
> 30mg/kg
Once absorbed, removal is difficult
IRON
Hepatic cell damage, shock, lactic acidosis
IRON
- Inital manifestation: vomiting, severe gastroenteritis, abdominal pain
IRON
IRON TОХІСІТУ Diagnosis:
• Serum iron concentration
• TIBC
IRON TОХІСІТУ
Treatment
• Supportive treatment (s&s)
• Emesis or gastric lavage
MERCURY Forms :
- Elemental or metallic - toxic when inhaled
- Mercurous/Mercuric - salt form
- Alkyl mercury - environmental pollutant
MERCURY Acute toxicity:
24 hr. urine levels
MERCURY Chronic toxicity:
hair analysis
MERCURY Treatment:
gastric lavage or emesis
most common toxin
LEAD
lead: highly toxic
Organic and inorganic LEAD
LEAD Fatal dose
• - chronic toxicity
• - acute toxicity
0.5mg absorbed day
0.5 g absorbed
- paint, toys, pencil, lipstick, gasoline,
LEAD TОХІСІТУ
Diagnosis
• AAS
•Anode stripping voltametry
LEAD
LEAD TОХІСІТУ
Treatment
• Supportive
• Gastric lavage
• Dilute MgS04 or Na2S04
• Chelating agents: dimercaprol, calcium disodium edetate & succimer
- esters of HPO4 or thiophosphoric acid
• Organophosphates
- synthetic derivatives of carbamic ac d
• Carbamates
• Widely used as pesticides
ORGAN HOSPRATE AND CARBAMATES
• Interfere with neurotransmission (acetylcholine)
ORGAN HOSPRATE AND CARBAMATES
• Parasympathetic manifestations: uncontrolled symptoms
ORGAN HOSPRATE AND CARBAMATES
• Salivation, lacrimation, urination and defecation
ORGAN HOSPRATE AND CARBAMATES
• Muscular weakness, tachycardia, hypertension.
ORGAN HOSPRATE AND CARBAMATES
• Confusion, slurred speech, ataxia, convulsions
ORGAN HOSPRATE AND CARBAMATES
ORGAN HOSPRATE AND CARBAMATES
Diagnosis
•Assay of cholinesterase activity
Treatment
• Respiratory support
• Gastric lavage or emesis
• Atropine
• Pralidoxime (organophosphate)
ORGAN HOSPRATE AND CARBAMATES
ENVIRONMENTAL CARCINOGENS
- aromatic compounds produced in cigarettes and in exhaust of engines
- Benzopyrene
→ lung cancer
- Benzopyrene
- preservative of red meat
- Nitrites
→ colon cancer
- Nitrites
- produced by Aspergillus
- Aflatoxin
→ hepatocellular carcinoma
- Aflatoxin
: benzene
- Aromatic hydrocarbon
→ acute leukemla
- Aromatic hydrocarbon
- angiosarcoma
- Vinyl chloride
- multiple malignancies
- Benzidine dyes
- lung cancer and mesothelioma
- Asbestos
(used in gas chamber)
Hydrogen cyanide
(floor cleaner)
Ammonia
(industrial solvent)
Toluene
(white ant poison)
Arsenic
(lighter fuel)
Butane
(insecticide)
DDT
(paint stripper)
Acetone
(Benzopyrene)
Pyrene *
(moth balls)
Naphthalene
(car batteries)
Cadmium *
(car exhausts)
Carbon monoxide
Known cancer causing substance
Vinyl chloride
- absorbed in SI
ETHANOL
- absorption time: 30 to 90 mins after ingestion
ETHANOL
- > 90% is metabolized by the hepatic cells to acetaldehyde and acetic acid
ETHANOL
: Ex. Lambanog
methylated spirits
: from vehicles/cars or radiator oil
methanol-containing antifreeze
- correlates w/ symptoms of toxicity and mortality
Glycolic acid
- given before anesthesia; to decrease secretion (salivation)
Atropine
- reverse muscle weakness/paralysis
Pralidoxime (organophosphate)
component of asphalt
Asbestos
used in equipment/manufacturing plants/machines
Asbestos
