Module 4-5 Midterm Flashcards
refers to a class of liquid organic chemicals
of variable lipophilicity and volatility, small molecular size, and lack of charge.
- Ready absorption: lung, skin, GIT
- Most are refined petroleum
- Classified according to mol. structure or functional grp
Solvent
Main Determinants of a solvent’s inherent toxicity:
C atoms
1,2,3 bonds bet. adjacent C atoms
Configuration
Halogenated
Presence of functional grp
is characterized by nonspecific symptoms (e.g., headache, fatigue, and sleep disorders) with or without changes in neuropsychological function.
CSE - chronic solvent encephalopathy
whether adverse health effects occur from solvent exposure is dependent on several
actors:
(1) toxicity/carcinogenicity
(2) exposure route
(3) amount or rate of exposure
(4) duration of exposure
(5) individual susceptibility
(6) interactions with other chemicals
reversible form of CSE, consists of symptoms only. “mild” and “severe” forms are accompanied by objective signs of neuropsychological dysfunction that may or may not be fully reversible.
neurasthenic syndrome
Types of solvents:
Inhalants
Solvent
VOC
a unique exposure situation, in that participants repeatedly subject
themselves to vapor concentrations high enough to produce effects as extreme as unconsciousness.
Solvent Abuse
they are volatile substances that can be inhaled to induce a psychoactive or mind-altering effect with vapor concentrations high enough to produce effects that resemble alcohol intoxication and may lead to unconsciousness.
Inhalants
breathed in through the nose or the mouth
“sniffing” or “snorting”
inhaling vapors from substances inside plastic or paper bags
“bagging”
solvent-soaked rag stffed into the mouth
“huffing”
occurs when the body is deprived of oxygen
Asphyxiation or suffocation
solid form but volatilize, mostly found in aerosol propellants, paint thinners, cleaners, and soil fumigants
VOC
2 important properties of solvents that govern their absorption and deposition in the
body:
Volatility & Lipophilicity
VOC
Absorption - alveoli; GIT
-> blood: air partition coefficients (PCs)
Transport, Distribution, Elimination
->Hepatic 1st-pass elimination
->Pulmonary 1st-pass elimination
Metabolism
->Bioactivation - can modulate the toxicities of solvents.
->CYP2E1 - catalyzes the oxidation
of halogenated and aromatic hydrocarbons causing cytotoxicity and/or mutagenicity.
N/A
is a “wasting” disorder that causes extreme weight loss and muscle wasting, and can include loss of body fat.
cachexia
Endogenous Factors:
Children
Elderly
Gender
Genetics
Exogenous Factors:
P450 Inducers & Inhibitors
Physical activity
Diet
Common name of Methanol
RoT: Ingestion
wood alcohol
MoT: 2 enzymes - Methanol > ? Formaldehyde >? Formic acid
alcohol dehydrogenase & aldehyde dehydrogenase
the presence of myoglobin in the urine, which usually results from rhabdomyolysis or muscle injury.
Myoglobinuria
ocular toxicity also known as? 18-48hrs
like standing in a snowfield
Treatment to Methanol (formic acid (FA) poisoning)
Fomepizole/Ethanol; Leucovorin/Folic Acid (vit. B9), w/i 30-60mins gastric aspirate, HD
this type of glycol is used as an antifreeze,
RoT: dermal, ingestion
CP:
- period of inebriation
- cardiopulmonary stage
- renal toxicity stage
Ethylene Glycol
Treatment for Ethylene glycol toxicity
emergency & supportive measures
Fomepizole/Ethanol; Pyridoxine, Folate, if recent - Thiamine lavage, HD
Generally considered safe by FDA
lactaldehyde-> lactate (acidosis)
Propylene Glycol
the ultimate toxicants
-alkoxy acetic acids
^alkyl chain = decreased reproductive & developmental toxicity; ^hematotoxicity
Glycol Ethers
major uses are in the production o rayon fiber, cellophane, and CCl4, and as a solubilizer or waxes and oils.
RoT: occupational
Carbon Disulfide (CS2)
Atropa, Datura, Hyoscyanmus, Solanum
Antimuscarinic - Blockade of muscarinic cholinoceptors
Adenium, Digitalis, Convallaria, Nerium
Cardiotoxic - Inhibition of cellular Na+ ,K+ -ATPase increases contractility, enhanced vagal effect
Anemone, Conium, Labrunum, Nicotinia, Ranunculus
Convulsants - Blockade of gamma-aminobutyric acid (GABA) receptor on the neuronal chloride channel, alteration of acetylcholine homeostasis, mimic excitatory amino acids, sodium channel alteration, hypoglycemia
Eriobotrya, Hydrangea, Prunus
Cyanogenic - Gastric acid hydrolysis o cyanogenic glycosides releases cyanide
Acotinum, Rhododendron, Veratrum
Dysrhythmia - Sodium channel activation
Conium, Laburnum, Lobelia, Nicotinia
Nicotinic - Stimulation of nicotinic cholinoceptors
Crotalaria, Heliotropium, Senecia
Pyrrolizidine - Pyrroles injure endothelium of hepatic or pulmonary vasculature leading to veno-occlusive disease and hepatic necrosis
Abrus, Ricinus
Toxalbumin - Protein synthesis inhibitors leading to multiple organ system failure
Toxic effects on skin:
Irritant contact dermatitis - Trichomes
Urtica sp
*mucuna pruriens (cow itch) *- mucinian
Allergic contact dermatitis
poson ivy
philopndendron scandens
Rhus sp.
Photosensitivity
Hypericum perfora (St. John’s wort) - hypericin
Toxic effects Respiratory Tract:
Allergic Rhinitis
Poa sp.
Festuca sp
Asteraceae family
Cough Reflex
Capsicum annuum & Casicum frutescens - Capsaicin & Dihydrocapsaicin
Toxic effects Gastrointestinal System:
Direct Irritant effects - NVD
Buffalo beans - quinolizidine alkaloids
Aesculus hippocastanum & Aesculus glabra - esculin
Antimitotic effects
Podophyllum peltatum - podophyllotoxin
Protein Synthesis inhibition
Euphorbiaceae
Ricinus communis - ricin I and II
