pesticides midterm reviews Flashcards
Key points for midterm exam. Only the stuff that requires extensive memorization
Organochlorines and pyrethroid works on ___synaptic neuron’s????
Organochlorines and pyrethroid work on PRE-synaptic neuron’s enzymes and membrane, disrupting ion dist
Organophosphate and carbamates work on ___synaptic cell???
Organophosphate and carbamates work on POST-synaptic cell by increasing ACh
Organochlorine insecticides include…
DDT, chlorinated-cyclodienes, -cyclohexene and chlordecone (kepone)
Organochlorin’es hormonal effect
estrogenic effect and enzyme-inducing properties interfering with fertility and reproduction
DDT and chlorinated-cyclohexanes cause….
paresthesia, dizziness, HA, N/V—-weight loss, anorexia, anemia
chlorinated cyclodienes and kepone cause…
HA, N/V, myoclonic jerking, seizures—-insomnia, anxiety, syncope, seizures
Kepone causes severe impairment of spermatogenesis
DDT MOA (mechanism of action)
DDT reduces K permeability, increases NA permeability and inhibits ATPase pumps. all leading to prolonged depolarization
chlorinated compound MOA
mimic picrotoxin which inhibit GABA. result in only partial repolarization.
Metabolism of organochlorine insecticides
very slow.
very lipophilic even after metabolism.
treatment of organochlorine
diazepam or phenobarbital for convulsions
Organophosphate/carbamate MOA
inhibition of AChEase.
OP covalently links with AChEase permenantly.
Carbamate can be removed from AChEase
Symptoms of OP/carbamate
miosis (pupil contriction), blurred vision, tearing, salivation, sweating, bradycardia, arrhythmia, bronchoconstriction, PE, twitching, weakness, HA, dizziness, confusion, syncope.
SLUD/DUMBELS
SLUD/DUMBELS
Salivation, Lacrimation, Urination, Diarrhea
Diarrhea, Urination, Miosis, Bronchorrhea, Emesis, Lacrimation, Salivation
OP/carbamate tx
Atropine: for hypersecretion and bradycardia. blocks binding of ACh to post-synaptic receptors.
2PAM for OP only: reverses permenant OP inhibition of ACHEase
OP/carbamate metabolism
extensive metabolism involving both phase 1 and 2
Pyrethroid insecticides use and classes
Used for pet flea control and vector control. Both inhibit Ca/Mg ATPase, increasing Ca level and NT release
Type 1 (non-cyano): shorter inactivation of nerve cell Na channel causing long afterpotential like DDT
Type 2 (alpha-cyano): longer anactivation of Na channel causing persistent depolarization and repetitive firing
Pyrethroid sx
dizziness, HA, seizure, resp sensitization (asthma) and allergic dermatitis
Pyrethroid Tx
decontamination, vit. E cream, and symptomatic therapy
Herbicides include…
dipyridyl compounds (paraquat, diquat), glyphosate, chlorophenoxy compounds (2,4,5-T and 2,4-D)
dipyridyl compound: Paraquat
skin toxicity: skin blisters and infection.
Leads to GI ulcers, liver damage/necrosis and pulmonary fibrosis (eventual target is lung)
Glycophosate MOA and Sx
eye and skin irritation, death if ingested large amount.
MOA on human unknown.
Chlorophenoxy compounds :2,4,5-T and 2,4-D
2,4,5-T aka “agent orange” has dioxin byproduct (carcinogen).
2,4-D has no dioxin byproduct.
CNS depression, skin/GI irritation, renal failure—anemia, hepatic/renal damage
Fumigant classes
Halogenated hydrocarbon (methyl bromide, DBCP, etc), inorganic compounds (sulfuryl fluoride), profumigants (metam sodium) and metal phosphides (Al, Zn, Mg)
Methyl bromide properties
high vapor pressure and odorless. Chlropicrin (tear gas) is added in commercial products for safety.
effect on ozone layers
Methyl bromide toxicity
acute: blisters, lower resp PE, CNS depression
chronic: cognitive/behavioral effect, teratogen, genotoxic and mutagenic.
Sulrufuryl fluoride toxicity
dyspnea, cough, PE, renal damage, weakness, seizure, N/V
Metam sodium toxicity
hydrolyzes to mixture of irritants.
irritant dematitis, asthma
metal phophides properties
colorless, fish/garlic smell.
Highly explosive and corrosive.
Rapidly oxidized to phosphoric acid.
metal phosphides sx
resemble viral syndrome. pulmonary and CNS toxicity. multi-organ failure
Fungicides effects
irritant and allergic dermatitis. Chronic dermatitis, possible carcinogen
fungicide–elemental sulfer
potent skin irritant and airway irritant.
MOA: redox byproduct of sulfur is allergy-inducing agent.
Rodenticides classes
Botanicals (red squill, strychnine), inorganics (phoshporous, thallium, zinc phosphide), anticoagulants
Regulatory mandate: FIFRA
by EPA.
gives EPA authority to control dist, sale and use of pesticides. require labeling, registration, etc.
regulation: FFDCA
allows EPA to establish tolerance for pesticides in food, drug and cosmetics
regulation: Worker protection standard
by OSHA for worker protection, training and stuff.
regulation: FQPA
by EPA.
health-based standards for pesticides in food. focuses on children
