Organochlorine Insecticide Flashcards Preview

Toxicology > Organochlorine Insecticide > Flashcards

Flashcards in Organochlorine Insecticide Deck (23)
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1
Q

What are the three classes of insecticide and examples of each?

A

Diphenylaliphatic compounds - DDT, methoxyclor

Arylhydrocarbon compounds - Lindaine, mirex, kepone

Cyclodiene insecticide - aldrin, chlordane, toxaphene

2
Q

How many months withdrawal for these chemicals?

A

2 months

3
Q

Which 2 are approved with limited use?

A

methyoxyclor and lindaine

4
Q

What should organochlorines not be confused with?

A

other chlorinated hydrocarbons

5
Q

Why have organochlorines been banned?

A

bioaccumulation, environmental persistance, estrogenic activity, endocrine discruption, egg shell thining, learning disorders, enzyme induction

6
Q

What is the absorption and distribution?

A

water insoluble and have low volatility
through skin and MM. poorly through lungs and GIT

accumulate in lipid tissues
- detect in liver, kidney, brain and fetus

7
Q

What is the metabolism and excretion?

A

slowly de chlorinated in the liver (metabolites are also toxic)

  • excreted primarily through the bile
  • enterohepatic recycling can occur
  • rapid mobilization of fat can enhance toxicity
8
Q

Although not fully understood what is the general MOA?

A

CNS excitation

9
Q

What is the MOA of DDT?

A
K efflux hindered
NA depolarization prolonged
= decrease transmembrane resting potential
= decrease firing threshold
= tremors or convulsions
10
Q

What other MOA are involved and what does this cause?

A
  1. increased synaptic activity
  2. increase NT release
  3. inhibition of gamma (GABA)

affect all neurons releaseing both inhibitory and excitatory
= variety of neurological problems
variable and dose dependent

11
Q

what animals are very susceptable?

A

sheep and cats

12
Q

What is the onset of clinical manifestations? toxic dose?

A

min to days depending on dose

15-100mg/kg in most species

13
Q

What are the 4 main clinical signs?

A

behavioural aberrations
nervous phenomena
autonomic manifestations
locomotor disturbances

14
Q

What are the behavioural aberrations?

A
anxiety, apprehension, frenzy
belligerance, aggression
head between legs
jumping over unseen objects
licking excessively
15
Q

What is the nervous phenomena?

A
hypersensitivity
muscle twitching, jaw champing
clonic tonic (stiff paddle)
tremors (increase temp)
opisthotonus
not blind
16
Q

What are the autonomic manifestations?

A
emesis in some
salivation
diarrhea
heart rate variable
dyspnea
17
Q

What are the locomotor disturbances?

A

stiff gait
incoordintation, atazia
possible circling to side of lesion

18
Q

What are the chronic manifestations of the poisoning?

A

similar but lesser

estrus cycling, decreased milk production or egg production

19
Q

does permanent damage occur in nervous system? can they recover?

A

if they survive acute yes

no permanent damage

20
Q

what are the PM findings?

A

can have non at all

non-specific:
mild hemorrhage and congestion in GI
mild fatty degeneration or cloudy swelling in liver and kidney
degenerative changes in thyroid, pancreas, testis or adrenal gland

21
Q

What is the Dx?

A

Hx, herd outbreaks, CNS manifestations with no PM finding

analysis of fat, milk, liver, kidney or GI contents recommended

22
Q

What is the treatment?

A
kill em
dermal - wash
GL
AC
mineral oil
sedation
reduce nutrition to lower fat
lipid emulsion
23
Q

What are the economic impacts?

A

milk residues

reproductive, carcinogenic and immunosuppressive effects in food animals