LEC 22 - Anti-Cestodals

Question 1

What are the five basic mechanisms that anti-parasitic agents use?

Answer 1

Neurotoxins, DNA inhibitors, Metabolic inhibitors, Protein synthesis inhibitors, Membrane inhibitors, and Development inhibitors

Question 2

Which of the five mechanisms are used against Helminths?

Answer 2

Neurotoxins and Metabolic inhibitors

Question 3

Which of the five mechanisms are used against external parasites?

Answer 3

Neurotoxins and Development inhibitors

Question 4

Which of the five mechanisms are used against protozoa?

Answer 4

DNA inhibitors, Metabolic inhibitors, Protein synthesis inhibitors, and developmental inhibitors

Question 5

What are the eight drug classes used as anti-helminthic drugs?

Answer 5

Isoquinolones, Chorsulon, Benzamidizoles, Piperazines, Imidathiazoles, Tetrahydropyrimidines, Macrocyclic lactones, and arsenicals

Question 6

What are the three types of helminths?

Answer 6

Cestodes, Trematodes, and Nematodes

Question 7

What types of drugs kill cestodes?

Answer 7

Isoquinolones

Question 8

What types of drugs kill Trematodes?

Answer 8

Chorsulon and Benzamidizoles

Question 9

What types of drugs kill Nematodes?

Answer 9

Benzamidizoles, Piperazines, Imidathiazoles, Tetrahydropyrimidines, and Macrocyclic lactones

Question 10

What does arsenicals kill specifically?

Answer 10

D. Immitis

Question 11

What is the basic anatomy of a tape worm?

Answer 11

Each segment has everything that it needs to reproduce

Question 12

What is the method which is approved in cattle to kill tapeworm?

Answer 12

None

Question 13

What are the two isoquinolones?

Answer 13

Praziquantal and epsiprantal

Question 14

What are the two types of benzamidazoles?

Answer 14

Albendazole and Fenbendazole

Question 15

What are the indications for praziquantel?

Answer 15

All tape worms in cats, dogs, and horses.

Question 16

What is the pharmodynamic process for praziquantel?

Answer 16

Altered intracellular homeostasis, causes direct/indirect disruption of cellular metabolism, causing tenanic paralysis/tegumentary breakdown, causing host response, leading to dead tapeworm

Question 17

How is praziquantel administered?

Answer 17

PO + IM + SC

Question 18

How well is praziquantel absorbed?

Answer 18

Completely absorbed by the PO route

Question 19

What is the BA of praziquantel?

Answer 19

Poor, due to first pass metabolism by liver

Question 20

Where does praziquantel distribute within the body?

Answer 20

All throughout

+ CNS

Question 21

How is praziquantel metabolized?

Answer 21

The metabolites produced are biologically active

Question 22

How is praziquantel eliminated?

Answer 22

Urine, t1/2 = 3 hours

Question 23

What are the adverse effects of praziquantel?

Answer 23

None, 5x the highest treatment dose is when it becomes toxic

Question 24

What is the use of Epsiprantel in dogs?

Answer 24

Dipylidium caninum and Taenia pisiformis

Question 25

What is the use of Epsiprantel in cats?

Answer 25

Dipylidium caninum and Taenia taeniaeformis

Question 26

How is epsiprantel adminstered?

Answer 26

PO

Question 27

How well is epsiprantel absorbed?

Answer 27

Very poorly absorbed

Question 28

How is epsiprantel distributed/metabolized?

Answer 28

Not distributed or absorbed. Eliminated in the feces

Question 29

How does epsiprantel work on cestodes?

Answer 29

Direct uptake of drug by the parasite, the host doesn't transfer the drug to the parasite like most of the other drugs

Question 30

How do immature flukes move through out the body?

Answer 30

Penetrate GI and traverse peritoneum to liver (4 days). Migrate through liver and feed on tissue causing damage. Penetrates main bile ducts (~ 8 weeks).

Question 31

What bacteria can immature flukes introduce into the blood stream?

Answer 31

Clostridium novyi

Question 32

How long does it take flukes to mature?

Answer 32

~ 10 to 12 weeks

Question 33

What pathologies do mature flukes cause?

Answer 33

Biliary hyperplasia and progressive occlusion

Question 34

When can chorsulon be used in the fluke life cylce?

Answer 34

AFTER 8 weeks post infection

Question 35

What is the chorsulon used for?

Answer 35

Fasciola spp. in cattle and sheep

Question 36

What is ivomec plus?

Answer 36

Chorsulon and ivermectin. Covers nematodes and flukes

Question 37

How does chorsulon work?

Answer 37

Stops glycolysis by inhibiting phosphoglyceromutase and phosphoglycerate kinase

Question 38

How is chorsulon adminstered?

Answer 38

PO and SC

Question 39

What is the BA for chorsulon?

Answer 39

55 to 60%

Question 40

What special considerations do you have to make when using chorsulon SC?

Answer 40

Only effective 10 weeks post infection

Question 41

How is chorsulon distributed throughout the body?

Answer 41

Remains in vasculature (75% in serum and 25% bound RBC)

Question 42

What does chorsulon bind to within RBCs?

Answer 42

Carbonic anhydrase

Question 43

How is chorsulon eliminated?

Answer 43

Unmetabolized, parent drug eliminated in urine

Question 44

When can albendazole work?

Answer 44

12+ weeks post-infection

Question 45

What is albendazole used for?

Answer 45

F. hepatica in cattle

Question 46

What is febendazole used for?

Answer 46

F. gigatica in sheep