Lecture 33: Ectoparasites Flashcards

1
Q

What 4 things should a good ectoparasiticide do

A
  1. Effective adulticide and repellant
  2. Persist at an effective dose on the skin for extended period (1-3 months)
  3. Be stable in sunlight, shampoo, water
  4. Cause minimal contamination in the local environment (reduce risk of resistance)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Individual ectroparasiticide agents are __ molecular weight

A

Large

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What large molecular weight of ectoparasiticides allows for what 4 things to occur

A
  1. Slow dermal absoprtion
  2. Low systemic bioavailability
  3. Large volumes of distribution
  4. Long tissue and plasma half lives
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are some advantages of topical ectoparasiticides

A

Avoid degradation in the GI tract, avoid first pass metabolism in the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are some disadvantages of topical ectoparasiticides

A

Risk of overdose (licking collar or skin), prolonged withdrawal times in food animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the routes of absoprtion for trans-epidermal absoprtion

A
  1. Transceullar- active transport
  2. Intercellular
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the routes of absoprtion for trans follicular absoprtion

A
  1. Trans-epidermal
  2. Sweat pore- accumulation of sebaceous glands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What species has the thickest and thinnest epidermal skin

A

Thickest: pigs
Thinnest: cats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are some indications for pyrethrins/pyrethroids

A
  1. Fleas and tickets
  2. 3rd generation chemicals have some mite and lice coverage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What 3rd generation pyrethrins/pyrethroids tx fleas, ticks, mites and lice

A

Permethrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

As you go from 1st generation to 4th generation pyrethrins/ pyrethroids how does stability and potency change

A

Increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the PD for pyrethrins/pyrethroids

A

Activates Na+ channels in nerves—> repetitive depolarizations leading to parasite death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

2nd generation pyrethrins pyrethroids are absolutely toxic to ___ because requires ___

A

Cats, requires glucoronidation metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are some signs of toxicity to pyrethrins/ pyrethroids

A

SLUDGE, miosis, tremors, convulsions, dyspnea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are 2 examples of drugs that are synergistic with pyrethrins

A
  1. Piperonyl butoxide
  2. N-octal bicycloheptene dicarboximide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the PD of piperonyl butoxide and N-octyl bicycloheptene dicarboximide

A

Blocks cytochrome p450, inhibits oxidative and hydrolytic metabolism, prevents enzymatic breakdown of pyrethrins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are some adverse effects with piperonyl butoxide

A

Prevents breakdown of pyrethrins in cats and increases toxicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Organophosphate are used for what

A

Pesticide control, anti-nematode agents, flea collars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is tetrachlorvinphos

A

Organophosphate collar to protect against fleas, ticks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the PD of organophosphates

A

Long lasting, irreversible inhibitors of AChE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are some signs of AChE inhibitor toxicity

A

SLUDGE, miosis and muscle spasms, bronchoconstriction, bradycardia, hypotension, seizures, respiratory paralysis, death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What cattle breeds are sensitive to organophosphates

A

Brahman, charolais, and simmental

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What dogs are sensitive to organophosphates

A

Greyhounds and whippets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What broad species is sensitive to organophosphates

A

Cats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is pralidoximine chloride used for

A

Reversible agent for AChE toxicity caused by organophosphotases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the PD for pralidoxime chloride

A

PAM binds organophosphate so it can’t bind to AChE receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Besides pralidoximine chloride what drug is another potential tx for organophosphate toxicity/ AChE inhibitor toxicity

A

Atropine

28
Q

T or F: pralidoxime chloride crosses BBB

A

False

29
Q

How is pralidoximine metabolized

A

Liver

30
Q

How is pralidoxime chloride excreted

A

Urine

31
Q

Do not use pralidoxime chloride unless indicated because also inhibits ___ and can cause signs similar to ___

A

AChE, organophosphate toxicity

32
Q

What is tx for organophosphate/ carbamate poisoning

A
  1. Administer atropine until pupils dilate and repeat q3-6hrs
  2. Administer pralidoxime chloride if less than 304hrs since exposure and repeat q8hrs
    3.intubate and ventilation
  3. Remove source of toxicity- bathe or sx
33
Q

T or F: you can treat carbamate toxicity with pralidoxime chloride

A

False, they have reversible binding and don;t have reactive phosphate so won’t work

34
Q

What is imidacloprid and nitenpyram indicated for

A

Fleas, especially resistant to fipronil

35
Q

Imidacloprid kills __ and __ within 1hr

A

Adults and larvae fleas

36
Q

Nitenpyram kills __ within 30 minutes

A

Adult fleas

37
Q

What is the fastest anti-flea drug

A

Nitenpyram

38
Q

Dog presents to your clinic with severe itching, you suspect fleas so before starting exam you give __ and after 30 minutes dogs stops itching which means ___

A

Nitenpyram, dog had fleas

39
Q

What is the PD for imidacloprid and nitenpyram

A

Agonist of the insects postsynpatic AChR NM receptor—> rigid paralysis/ tetanus

40
Q

What is the t 1/2 if imidacloprid and nitenpyram in dogs and cats

A

Dogs: 2.8hrs
Cats: 7.7hrs

41
Q

What are some adverse effects of imidacloprid

A

Nicotine and hepatic effects if ingested- don’t give orally

42
Q

What is fipronil indicated for

A

fleas, ticks, biting lice, ear parasites and Trombicula automnalis

43
Q

What is the PD of fipronil

A

Non-competitive inhibitor of glutamate activated chloride channels -> rigid paralysis and CNS disruption

44
Q

What is fluralaner and afoxolaner indicated for

A

Treatment and prevention of fleas and some ticks in dogs

45
Q

What is the PD of Fluralaner

A

Inhibit insect GABA receptors and also glutamate activate chloride channels—> rigid paralysis and CNS disruption

46
Q

What is Pd of afoxolaner

A

Inhibit insect GABA receptor

47
Q

What are some adverse effects of fluralaner and afoxolaner

A

Vomiting, inappetence, diarrhea, hypersalivation

48
Q

What is amitraz indicated for

A
  1. Generalized demodex in dogs and demodicosis in cats
  2. Fleas and ticks on dogs
  3. Ticks, mites and lice on swine and cattle
49
Q

Taktic, generic form of amitraz can kill what species

A

Horses and dogs

50
Q

What I the PD of amitraz

A

MAO inhibitor that acts prefentially in mites over mammals, causes toxic catecholamin(NE, epi) levels in mites

51
Q

What are some adverse effects of amitraz

A

Alpha2 adrenergic agonist in mammals —> sedation, bradycardia, vomiting, diarrhea, ataxia

52
Q

__ administration is most common cause of toxicity, for example ingesting ___

A

PO, impregnated collar

53
Q

What breeds/species are specifically suspceptible to amitraz toxicity

A

Toy breeds, dogs < 4months, cats, and rabbits

54
Q

What is the reversal agent for amitraz

A

Atipamezole

55
Q

What is juvenile hormone analog indicated for

A
  1. Fleas in dogs and cats
56
Q

What is the PD of junvenile hormone analogs

A

Maintains/ increases hormone levels so fleas don’t mature

57
Q

Pyriproxygen (JHA) concentrates in flea __ and creates ___

A

Ovaries, non-viable eggs

58
Q

Pyriproxygen is more stable to UV light than

A

Methoprene

59
Q

What are some adverse effects of juvenile hormone analogs

A

Very safe by themselves but when used in combination products that have permethroids can be toxic to cats

60
Q

What is sentinel used for

A

Fleas in dogs and cats

61
Q

What is the PD of sentinel

A

Drug consumed by fleas in blood, flea larvae feeding on adult flea feces also ingest drug and it inhibits the production of chitin exoskeleton during pupal stage of development (insect development inhibitors)

62
Q

What are some adverse effects of sentinel (insect development inhibitors)

A

Injection site reactions, very severe in dogs

63
Q

What are some examples of insect repellents

A
  1. Butoxypolypropylene
  2. Di-n-propyl isocinchomeronate
  3. Diethyl-m-tulamide (DEET)
64
Q

What are the effects of insect repellents

A

Reduce insects landing on/ entering the hair coat of animals interfere with ectoparasiticides feeding, ectoparasite disorientation

65
Q

What are some adverse effects of DEET (repellent)

A

Increase dermal absorption and increase adverse effects of primary ectoparasiticides in cats