Anthelmentics

Introduction:

• Tropical diseases caused by parasitic worms (multicellular organism) which infest the body are called as helminth.

• The three main families of worms that infest human being belong to two phyla.

1. Nematodes /nemathelminthes (round worm)

2. Platyhelminthes

i) Cestodes  (tape worm )

ii)Trematodes

• Most of the people carry one or another type of parasite in intestine .among the nematodes, hook worm causes dangerous infestation as they remains attached to wall of intestine and suck the blood.

Other nematode infection are following

i) Safaris (round worm)

ii)Thread worm

iii) Whip worm

iv) Guinea worm

v) Pin worm

vi)Trichinosis

• Cestodes are unpleasant but do not cause serious illness.

• The Trematodes infestations contributing to death is Schistomiasis (blood flukes or bilharzias) is when penetrating the unbroken skin to veins and causing slow destruction of liver and kidney.

• This parasite cause abdominal pain, anorexia, diarrhea with blood and mucus, enlarged liver

Definition: - Anthelmentics are the drugs which are used to combat (appose) any type of helminthiasis (Helmenthic infections)

Classification of Anthelmentics:-

1. Halogenated hydrocarbon:-e.g. Tetrachloroethylene.

2. Halogenated phenol and biphenyl:-e.g. Bithinol

3. Dyes: - Gentian violet

4. Piperazine and related compound:-e.g. Piperazine citrate, DEC.

5. Other heterocyclic ring containing compound:-E.g.Mebendazole, (benzimidazole) niridazole (imidazole).

6. Alkaloids: - e.g.-Emetine

7. Antimonial compound:-e.g. –Antimony Potassium Tartarate

Piperazine

Structure of Piperazine:

Properties of Piperazine:-

1. Piperazine hexahydrate is colourless and glassy with deliquescent crystal having faint characteristics odour.

2. It is freely soluble in water and alcohol.

3. Very slightly soluble in ether.

4. It is official as its citrate, phosphate and adipate salt.

5. Ii is an ideal Anthelmentics agent.

6. It is nontoxic at therapeutic dose level and palatable in conventional formulation

7. It remains a drug of choice for therapy of ascaris and pinworm.

8. It blocks the neuromuscular transmission in ascaris at myoneural junction.

9. The worm is paralyzed and is unable to resist peristalsis and thus expelled with the stool.

Chemical properties of Piperazine:-

• When Aqs. Solution is treated with potassium fericynide solutions in presence of mercury and sodium bicarbonate, a red colour slowly produced.

Stability and storage of Piperazine:-

• It is deliquescent and affected by light .hence it is stored in tightly closed light resistant containers.

Uses of Piperazine:-

It is used to treat:

1. Pinworm infestations (enterobiosis)

2. Round worm infestations (ascariasis )

Pharmaceutical formulations of Piperazine:-

1. Piperazine citrate elixir.

2. Piperazine citrate tablets.

Brands names of Piperazine:

1. Antepar

2. Helmacid

3. Wormicid

DEC / diethyl carbamzine

Structure of Diethyl carbamzine:

Chemical name:-N, N diethyl 4 –methyl Piperazine -1 carboxamide.

Properties of Diethyl carbamzine:

1. It is official as citrate salt.

2. It is white crystalline powder.

3. It is odourless.

4. It has bitter taste.

5. It is soluble in water

6. It is practically insoluble in chloroform and ether.

Stability and storage of Diethyl carbamzine:-

• It is stored in tightly closed containers.

Uses of Diethyl carbamzine:

It is used to treat:-

1. Round worm infestations 

2. Filarial infection

a) Ochocerciasis (river blindness)

b) Lymphatic filariasis

3. Loiasis (infection due to Loa Loa)

4. Tropical eosinophilia

Pharmaceuticals formulations:-

1. Diethylcarbamazine injection

2. Diethylcarbamazine tablets

Brand Names:

1. Filazine

2. Hetrazen

3. Bonocide forte.

Mebendazole

• It is benzimidazole derivatives and contains methyl carbamate (-NHCOOCH3 group at C2 position and benzoyl group at C5.

Physical Properties of Mebendazole:

1. It is white or slightly yellow powder,

2. It is practically insoluble in water.

Stability and storage of Mebendazole:-

• It is stable under normal condition of temperature, light and moisture .it is stored in well closed containers.

Uses of Mebendazole:

it is broad spectrum Anthelmentics, it is used to treat.

1. Whipworm infestation

2. Round worm infestation

3. Tape worm infestation

4. Thread worm infestation

5. River blind ness.

6. Hookworm infestation

7. Guinea worm infestation

8. Capillaria infestation  

Pharmaceutical formulations:-

Mebendazole tablets

Brands names:

1. Mebex

2. Wormin

3. wormokil