A-27 Anthelmintics (benzimidazoles, imidazothiazoles, tetrahydropyrimidines)

Question 1

Must know drugs Benzimidazole

Answer 1

Albendazole
Fenbendazole
Flubendazole
Triclabendazole
Febantel

Question 2

Must know drugs Imidazothizole

Answer 2

Levamisole

Question 3

Must know drugs Tetrahydropyrimidine

Answer 3

Pyrantel

Question 4

Action of antihelmintics

Answer 4

Expel parasite by :
Stunning
Killing
Have a selective toxicity to parasite

Question 5

Antinemadotals

Answer 5

Against roundworm

Question 6

Anticestodal

Answer 6

Against tapeworm

Question 7

Antitrematodals

Answer 7

Against flukes

Question 8

Types of benzimidazole

Answer 8

Benzimidazole carbamates (halogenated)
Pro Benzimidazole

Question 9

Mechanism of action of Benzimidazole

Answer 9

Tubular polymerisation inhibition
So inhibition in cell transport & E metabolism

Question 10

Spectrum of Benzimidazole

Answer 10

AT, AC, AN
Antiparasitic/fungal/viral/tumor effect

Question 11

Benzimidazole only for liver flukes

Answer 11

Triclabendazole

Question 12

Resistance of Benzimidazole

Answer 12

Ru: GI roundworm
Swine: oesophagostomum
Eq: strongylus
Ca: blood sucking nematodes

Question 13

PK : abs of Benzimidazole

Answer 13

Poor in GI ( except Albendazole & oxfendazole) last 6-30 h
Slowed by rumen & eq caecum
Feed decreases activity

Question 14

Pk: met of Benzimidazole

Answer 14

Rumen acts as drug reservoir
Febantel oxidised to Fenbendazol then Oxfendazole

Question 15

Pk: excr. Of Benzimidazole

Answer 15

Biliary, both (parent & metabolites) eliminated with faeces

Question 16

Administration of Benzimidazole

Answer 16

PO relitavely safe

Question 17

Toxicity of Benzimidazole

Answer 17

Teratogenic
Hepatotoxic, feather/hair loss (prolonged use)
Neurotoxic (large dose)

Question 18

Specie application of Febantel

Answer 18

Ca
Fe

Question 19

Species application of Flubendazole

Answer 19

Ca
Fe
Sus

Question 20

Species application of Mebendazol

Answer 20

Ca
Fe
Eq

Question 21

Species application of Fenbendazole

Answer 21

Ca
Fe
Eq
Sus

Question 22

Species application of Albendazole

Answer 22

Ru

Question 23

Species application of Triclabendazole

Answer 23

Ru, only for liver flukes

Question 24

Mode of action of imidazothiazoles

Answer 24

nAch receptor agonist —> paralysis

Question 25

Imidazothiazole spectrum

Answer 25

AN, larvicidal (migrating stage) & adultcidal

Question 26

Imidazothiazole resistance

Answer 26

Ru: GI nematodes Cross resistance with Morantel

Question 27

Pk of Imidazothiazole

Answer 27

A: rapid Excretion: rapid, urine

Question 28

Administration route of levamisole

Answer 28

PO SC in sheep (short WP, 0 days for milk)

Question 29

Toxicity of levamisole

Answer 29

NARROW TI Kuvasz dogs are very sensitive Cats and horses too

Question 30

Side effects of levamisole

Answer 30

Salivation, tremors, ataxia, urination, defecation , collapse, asphyxia

Question 31

Antidote in case of Levamisole toxicosis

Answer 31

Atropine

Question 32

Mechanism of action of tetrahydropyrimidines

Answer 32

Cholinomimetic —> paralysis

Question 33

Tetrahydropyrimidines spectrum

Answer 33

AN, adult gut worms & larval stages

Question 34

PK of pyrantel

Answer 34

Abs: Good in Sus & ca Bad in Ru Met: rapid Excr: urine

Question 35

Pk of Morantel

Answer 35

Abs: good in SI Met: liver (short WP & 0 milk) Excr: urine

Question 36

Species application of pyrantel

Answer 36

Ca Fe Eq PO

Question 37

Species application of Morantel

Answer 37

Bolus: Cattle Oral suspension: Sheep

Question 38

Tetrahydropyrimidines resistance

Answer 38

Migrating larvae Whipworms (except oxantel)

Question 39

Toxicity of Tetrahydropyrimidines

Answer 39

Cholinergique signs Antidote : atropine Morantel is safer in Ru