Kumar's Final Review - Anti-Helmenthics - AH

Question 1

What are the Anti-nematodal (roundworm) drugs?

Answer 1

BZDs, Levamisole, Pyrantel/Morantel, Dichlorvos, Macrocyclic lactones, Piperazine, HW adulticides

Question 2

What drugs are anti-cestodal (tapeworms)?

Answer 2

Dichlorphen, Resorantel, Praziquantel, Epsiprantel, BZDs

Question 3

What drugs are anti-trematodal (flukes)?

Answer 3

Bithionol, Nitroxynil, Salicylanilides, Sulfonamides (clorsulon), and BZDs (albendazole and triclabendazole)

Question 4

BZD MOA?

Answer 4

Irreversibly binds to nematode Beta-tubulin → inhibition of microtubules

Question 5

Adverse effects of BZDs?

Answer 5

Contraindicated in pregnancy → teratogenic

Question 6

Which group of BDZs are also effective against cestodes?

Answer 6

Carbamates: Mebendazole (taenia), oxibendazole, Albendazole, Fenbendazole

Question 7

What are the two proBZDs?

Answer 7

Albendazole → Netobimin. Fenbendazole → Febantel.

Question 8

What happens to the sulphoxide in the proBDZs?

Answer 8

They are later converted to sulphoxones

Question 9

MOA of Imidazothiazoles?

Answer 9

Neuromuscular blockade (never combine)

Question 10

How are Imidazothiazoles administered?

Answer 10

Oral, parenteral (SC) or topical

Question 11

Name a Imidazothiazole that is a l-isomer of dl-tetramisole

Answer 11

Levamisole

Question 12

MOA of Levamisole (2)

Answer 12

1. Ganglionic stimulant and direct cholinergic drug. Binds to nicotinic receptors of nematode parasites → depolarization blockade. 2. immunostimulator (CMI)

Question 13

Margine of safety for Levamisole?

Answer 13

narrow margin of safety. Safety factor is twice that of Tetramisole.

Question 14

What increases the toxicity of lavamisole?

Answer 14

simultaneous admin of pyrantel tartrate

Question 15

What animals should you avoid giving Levamisole to?

Answer 15

Lactating dairy animals

Question 16

Why do you need to wear gloves when handling Levamisole?

Answer 16

Percutaneous absorption → blood disorders/ fatal agranulocytosis

Question 17

What drugs are included in Tetrahydropyrimidines group?

Answer 17

Pyrantel and Morantel

Question 18

Which is safer, pyrantel or morantel?

Answer 18

morantel

Question 19

MOA of Tetrahydropyprimidines?

Answer 19

Depolarization blockade → paralysis of nematode

Question 20

How are Tetrahydropyprimidines administered?

Answer 20

Oral only → GI nematodes and lungworms

Question 21

What animals should not be given Organophosphate compounds?

Answer 21

Ill or stressed patients

Question 22

What can be used to treat pinworms?

Answer 22

Pamoate salt – not soluble → GI

Question 23

What organophophate can be incorporated into polyvinal pellets?

Answer 23

Dichlorvos

Question 24

What Organophophate is effective against Whipworms Trich spp.?

Answer 24

Dichlorvos

Question 25

Dichlorvos MOA?

Answer 25

irreversible inhibition of AchE → paralysis of nematodes

Question 26

MOA of Macrocyclic Lactones?

Answer 26

Binds to Cl- channels → increase in GABA → hyperpolarization → flaccid paralysis of parasite and expulsion

Question 27

What are the two main categories of Macrocyclic Lactones?

Answer 27

Avermectins and Mibemycins

Question 28

What are the 5 Avermectins?

Answer 28

Ivermectin, Doramectin, Eprinomectin, (Selamectin, Abametin)

Question 29

What Avermectin can't be given to collies, aussies or murrah gray cattle?

Answer 29

Ivermectin

Question 30

Which Avermectin has a low milk plasma ratio and can be used in dairy cows?

Answer 30

Eprinomectin

Question 31

Which Avermectin can be used in the Tx of screw worms and Myiasis?

Answer 31

Doramectin

Question 32

Prophylactic against H Ws → micro filaricide

Answer 32

Mibemycins

Question 33

What are the two Mibemycins?

Answer 33

Milbemycin Oxime and Moxidectin

Question 34

Piperazine class spectrum?

Answer 34

Narrow

Question 35

Drugs in the Piperazine class include?

Answer 35

Piperazine and Diethylcarbazine (DEC)

Question 36

When should you avoid giving Piperazine?

Answer 36

In animals with chronic liver Dz and in heavy ascarid infxns → intestinal impaction or rupture

Question 37

how is Diethylcarbazine used?

Answer 37

As a prophylactic HW Tx – adult stages of nematode only (no microfilaria)

Question 38

What needs to be done before Tx with DEC?

Answer 38

Dog should be cleared of adult and larval microfilaria or risk anaphylaxis

Question 39

Tx timing for DEC?

Answer 39

Restart Tx 4 weeks after the first Tx

Question 40

What are the two heartworm adulticides?

Answer 40

Thiacetarsamide sodium and Melarsomine

Question 41

Which HW adulticide is safest and more potent?

Answer 41

Melarsomine

Question 42

Toxicity of Thiacetarsamide Na?

Answer 42

Nephrotoxicity and Hepatotoxicity

Question 43

Restorantel can be used to treat?

Answer 43

Rumen flukes (parphistomeum) and Moneizia spp. In ruminants

Question 44

Which anti-cestodal is only used to tx cectodes?

Answer 44

Episprantel

Question 45

Praziquantel spectrum?

Answer 45

Wide = adult and larval cestodes and trematodes (shistosomes)

Question 46

Vd of praziquantel?

Answer 46

well absorbed and distributed

Question 47

MOA of Praziquantel?

Answer 47

Centres on Ca++ ion flux across the surface membranes of the exposed parasite. Adult cestodes –release >of Ca from mm stores. In schistosoma –Ca >is taken up –mm >contraction –paralysis.> In both –vacuolization >--blebs –burst >and create leasons though which neutrophilic/eos granulocytes can enter and cause lysis > >

Question 48

What does Closantel treat?

Answer 48

Mature and immature stages of flukes. Effective against resistant strains of H. contortus

Question 49

MOA of closantel?

Answer 49

Proton Ionophor: Uncouples oxidative phophorylation

Question 50

Clorsulon MOA?

Answer 50

inhibits glycolytic pathway → inhibition of ATP production

Question 51

Rafoxanide MOA?

Answer 51

Protein Ionophor: Uncouples oxidative phophorylation → decreased ATP production

Question 52

Which anti-trematodal is FDA approved for liver flukes?

Answer 52

Clorsulon

Question 53

Which anti-trematodal is highly protein bound (99%) with a half life of 17 days?

Answer 53

Rafoxanide

Question 54

Which anti-trematodals are broad spectrum for immature and mature flukes?

Answer 54

Rafoxanide and closantel

Question 55

Which anti-trematodal has metabolites that remain protein bound for 7 days?

Answer 55

Ticholrbendazole

Question 56

What drug is 100% effective against immature F. heptica?

Answer 56

Diamphenethide