Antihelmintic drugs

Definition: Drugs that are used to eradicate or reduce the numbers of helminthic parasites in the intestinal tract or tissue of the body.

Administration of durg: Oral,should be taken with water during or after meals.

Contraindication:           

1)      Pregnancy(The drugs are teratogenic & embryotoxic abortion).

2)      Gastro-intestinal ulcer.

3)      Below 2 yrs, of baby.

4)      Sever liver disease.

Classify anthelmintics:

[A]Neuromuscular blocker of parasite:

·         Piperazine.

·         Pyrantel pamoate.

[B]Paralysis of worm & expel in faces:

·         Levamisole.

·         Bephenium.

[C]Inhibit ATP synthesis of parasite:

·         Mebendazole.

·         Albendazole.

·         Thiabendazole.

[D]Destroy scolex:

·         Nicolsamide.

Clinically used imptant drugs for Helminthiasis:Mebendazole,Albendazole,Pyrantel pamoate.

Mebendazole:        

Synthetic benzimidazole.

It has a wide spectrum of anthelmintic activity & low incidence of adverse effects.

It can be taken before & after meal.                     

It is metabolized in liver & excretde through kidney.

Describe the Mebendazole & Albendazole:

	Mebendazole	Albendazole
M/A	It inhibits microtubule  synthesis in nematods → Irreversibly impair glucose uptake→↓ATP→Parasites are  immobilized→ Die slowly→ Cleared from GIT within several days.	1.It blocks glucose uptake by parasite. 2.Depleting their glycogen stores. 3.Decreasing formation  of ATP. As a result the parasites is immobilized and dies.
Dose	100mg twice daily for 3 days. Treatment can be repeated after 2 to 3 wk.	A single dose of 400mg.
Indication	1.Round worm. 2.Hook worm. 3.Whip worm. 4.Combined infection. 5.Pin worm.[100 mg once. Repeat the treatment 2 to 4 wk after]	1.Round worm. 2.Hook worm. 3.Whip worm. 4.Combined infection. 6.Thread worm.
Adverse  effect	1.Mild nausea,vomiting. 2.Diarrhoea. 3.Abdominal pain. 4.Headache,Dizziness. 5.Hypersensitivity recation. 6.Occasionally pruritus,rash eosinophilia.	1.Mild and transient  epigastric distress, nasuea,diarrhea. 2.Headache,diazziness ,lassitude and insomnia.
Contraindication	1st trimester of pregnancy,used with caution below 1 year of age.	1.Patient with known  hypersensitivity to  other benzimidazole  drugs or to those  with cirrhosis. 2.Pregnancy. 3.Children younger than 2 years of age.

                                                                                                                                           (Ref:Katzung-11th,P-923-931)