Benzimidazoles are heterocyclic organic compounds used to treat infections from roundworms, tapeworms, lungworms, and liver flukes. They act by uncoupling oxidative phosphorylation in flukes, inhibiting the fumarate reductase enzyme and impairing glucose uptake, decreasing ATP synthesis and killing the parasite. Common drugs include albendazole, fenbendazole, and triclabendazole, which are dosed based on species and weight. Side effects can include headaches, nausea, and vomiting, while rare but serious effects include acute renal failure and hepatotoxicity. Benzimidazoles are contraindicated during pregnancy, lactation, or for hypersensitive or younger animals.

1. BENZIMIDAZOLES
Md. Saheb Ali
Faculty of Veterinary Science
Bangladesh Agricultural University

2. Outline
Definition
Indication
Mode of action
Pharmacological dose
Available drugs in BD
Side effect
Contraindication

3. BENZIMIDAZOLES
Benzimidazoles is a heterocyclic
organic compound.
This bicyclic compound consists of
fusion of benzene and imidazole.
It is a colorless solid.

4. Indications:
Infections against
 Round worm
 Tape worm
 Lung worm
 Liver fluke

5. MODE OF ACTION
Acts as a uncoupling oxidative
phosphorylation in fluke.
They inhibit the fumerate
reductase enzyme, impaired
glucose uptake thereby
decrease ATP synthesis and
killed the parasite.

6. Pharmacological Dose
Albendazole: Cattle: @ 7.5 mg/kg bwt
Sheep & Goat @ 5 mg/kg bwt
Fenbendazole: Cattle: @ 7.5 mg/kg bwt
Dog & Cat: @ 100 mg/kg bwt
Horse: @ 5-10 mg/kg bwt
Triclabendazole: Cattle: @ 12 mg/kg bwt
Sheep & Goat: @10 mg/kg bwt

7. Common Trade Names of
Benzimidazoles
Tab. Albentic vet @ 1 tab/80 kg bwt
Bol. Almex @ 1 boli / 80 kg bwt
Tab. Helmex @ 1tab/80 kg bwt
Bol. Acinex @ 1 tab/75 kg bwt
Bol. Endex @ 1 boli/70 kg bwt
Bol. Fenvet @ 1 boli/ 50 kg bwt

8. Side Effects
Common: Headache, Abdominal
pain, Nausea, Vomiting.
Rare: Fever, skin rash, itching,
thining or loss of hair, unusual
tiredness and weakness.
Serious: Acute renal failure,
Granulocytopenia, Hepatotoxicity
and leucopenia

9. Contraindication
Pregnancy
Lactation
Hypersensitive animals
Younger animals