1. Anthelmintic Drugs

2. Helmintic infections

3.  Human is the primary host for most helminthic infections.  Most worms produce eggs and larva  These pass out of human body and infect secondary host  Immature forms invade humans via skin or GIT

4. Types of worms  Worms live in host, s alimentary canal  Worms or larvae live in muscles, viscera, menninges, lungs. Subcutaneous tissues

5. Intestinal Worms A) Round worms ( Nematodes )  Ascaris lmubricods ( common )  Enterobius vermicularis ( pin worm)  Trichris trichuria ( whip worm)  Strongyloids stercoralis ( thread  Ankylostoma dudenale ( hook worm

6. B) Tape worms ( cestodes )  Taenia saginata ( Beef)  Taenia solium ( pork) Humans become infected by eating raw or unde cooked meat containing larvae of infected cattle or pig

7. Continue ( cestodes )  In some cases the larva gets encysted in muscles, viscera, brain, eye resulting in cysticercosis

8. Tissue worms  Filariae ( bancrofti, loa loa ) Adult filariae live in the lymphatics, causing lymphadenitis, swelling of limb. Microfilariae goes to blood stream to be ingested by mosquitoes  Trichnella spiralis : larva migrats from intestine to tissues of leg or foot producing ulcer

9. Anthelminthic Drugs May act by causing :  paralysis of the worm.  damaging the worm leading to partial digestion or rejection by immune mechanisms.  interfere with the metabolism of the worm.

10. Ascaris lumbricoids ( common round worm)

11. filariasis

12. Hookworm

13. Pinworm male,female

14. Tapeworm

15. whipworm

16. Dircrocoelium dendriticum

17. Fasiola hepatica

18. Tricuris tricura

19. Trichinela spiralis

20. elephantiasis

21. Hydateid cyct

22. cysticercosis

23. ANTHELMINTIC DRUGS ALBENDAZOLE  Broad spectrum  Drug of choice for treatment of hydatid disease and cysticercosis.  Used for the treatment of ( intestinal nematodes ) e.g. ascariasis, tricurasis and strongyloidiasis, pinworm, hookworm

24. Mechanism Of Action  Inhibits microtubule synthesis that irreversibly impairs glucose uptake, intestinal parasites are immobilized and die slowly.  larvicidal in : hydatid,cysticercosis, ascariasis and hook worm infections.  Ovicidal in ascariasis,hookworm, trichuriasis

25. Pharmacokinetics  Benzimidazole carbamate  Administered orally, absorption increased with a fatty meal  Metabolized in the liver to the active metabolite albendazole sulfoxide

26. Pharmacokinetics  Plasma half life 8-12 hours  sulfoxide is mostly protein bound distributes well to tissues and enters bile, CSF & hydatid cysts.  Metabolites are excreted in urine

27. Clinical uses  Used on empty stomach when used against intraluminal parasites but with a fatty meal when used against tissue parasites.  In ascariasis,trichuriasis,hookworm, pin worm infections : children over 2 years & adults (single dose 400mg, repeated for 2-3 day in heavy ascaris infection. For 2 wks for pin worm infection 2. Hydatid diseases

28. Albendazole (con’) 3.Neurocysticercosis: Used with corticosteroid to decrease the inflammation caused by dying organism and it also reduces the duration of course for 21 days 4. Other infections: Drug of choice in cutaneous and visceral larva migrans, intestinal capillariasis & others

29. Adverse Effects  In short term(1-3 days): No significant adverse effects  In long term use : abdominal pain, headache,fever,fatigue, alopecia, increased liver enzymes, pancytopenia.  Not given during pregnancy, hypersensitive peoples & children under 2 years.

30. MEBENDAZOLE (Vermox)  Synthetic benzimidazole  Wide spectrum and safer than albendazole Mechanism of action: As albendazole It kills hookworm, pin worm, ascariasis and trichuris eggs.

31. Pharmacokinetics  less than 10% of orally administered drug is absorbed  Absorption increases with fatty meal.  Absorbed drug is 90 % protein bound  Converted to inactive metabolites.  Half- life of 2-6 hours  Excreted in urine.

32. Clinical Uses Tablets should be chewed before swallowing.  Pinworm, trichuriasis, hookworm & ascaris infections.  in adults and children over 2 years cure rate is 90-100 % except hookworm it is less.

33. Adverse Effects & Precautions  Short term therapy.Mild GI disturbance.  High dose : hypersensitivity reactions, agranulocytosis, alopecia,elevation of liver enzymes. Used with caution under 2ys of age may cause convulsion. Contraindicated in pregnancy..

34. Thiabendazole  Mechanism as other benzimidazole  Chelating agent and form stable complexes with metals including iron, but does not bind with calcium.  Rapidly absorbed  Half- life of 1-2 hrs  Completely metabolized in liver and 90% is excreted in urine  Can also absorbed through skin

35. Clinical uses  Should be given after meals.and tablets should be chewed  Strongyloidal infections  In cutaneous larva migrans.Thiabendazole cream is applied topically or drug can be given orally for 2 days.

36. Adverse Effects & Contraindications  More toxic than other benzamidazoles  GI disturbances  Pruritus,headache, drowsiness, psychoneurotic symptoms.  Irreversible liver failure.  Fatal Stevens –Johnson syndrome  Not used in young children, pregnancy, hepatic and renal diseases.

37. PYRANTEL PAMOATE Broad spectrum Pharmacokinetics :  Poorly absorbed orally  Half of the drug is excreted unchanged in the feces. Mechanism of action :  Neuromuscular blocking drug leads to paralizes of worms Effective  against luminal organisms( mature or immature forms).  Not effective against migratory stages in the tissues or against ova

38. Clinical uses  Pin worm given orally with or without food.  Ascariasis  Hookworm

39. Adverse Effects  Infrequent mild GI disturbance  drowsiness, headache,insomnia.  Rash,fever Contraindications  Pregnancy  Children under 2 years of age

40. PIPERAZINE  Only recommended for the treatment of ascariasis cure rate 90% for 2 days treatment.  Readily absorbed orally and excreted mostly unchanged in urine  Mechanism of action: Causes paralysis of ascaris by blocking acetylcholine at myoneural junction, the live worms expelled by normal peristalsis.

41.  Treatment is continued for 3-4 days or repeated after one week in case of heavy infections.

42. Adverse Effects  GI disturbance  Neurotoxicity, allergic reactions. Contraindications  Epilepsy  Impaired liver or kidney functions  pregnancy

43. NICLOSAMIDE  Second-line drug for treatment of tape worm infections. Mechanism of action:  Adult worm is rapidly killed by inhibition of oxidative phosphorylation. Pharmacokinetics:  Poorly absorbed from gut & excreted in urine.

44. Clinical Uses  Treatment of most forms of tapeworms.  Not effective against cysticercosis or hydatic disease.  Given in the morning on empty stomach.  Purgative is necessary to purge all dead segments& prevent liberation of ova.

45. Adverse effects  Mild,infrequent and transitory GI disturbance  Alcohol consumption should be avoided  Not indicated in children under 2 years of age or in pregnancy.

46. DIETHYL CARBAMAZINE  Drug of choice for the treatment of filariasis and tropical eosinophilia. Pharmacokinetics:  Rapidly absorbed from gut  Half- life is 2-3 hours  The drug should be given after meals  It is excreted in urine as unchanged or metabolite.  Dosage is reduced in urinary alkalosis and renal impairment.

47. Mechanism Of Action  Immobilizes microfilariae and alters their surface structure,displacing them from tissues & making them susceptible to destruction by host defense mechanism

48. Adverse Effects  Fever, malaise, papular rash, headache, GI disturbance,cough. Chest,muscle,joint pain  Leucocytosis  Retinal hemorrhage  Encephalopathy  lymphangitis and lymphadenopathy.  *It is not teratogenic

49. Contraindications & Cautions  * Hypertension  * Renal disease *patient with lymphangitis Patients suspected of malaria

50. IVERMECTIN  Drug of choice for treatment of filaria & strongyloidiasis  It is a macrocyclic lactone ring  Given only orally  Rapidly absorbed  Does not cross BBB.  Half- life is 16 hrs  Excretion in urine & feces.

51. Mechanism Of Action  Paralyze nematodes by intensifying GABA- mediated transmission of signals in peripheral nerves.

52. Clinical uses  Drug of choice for cutaneous larva migrans & strongyloidiasis.  Onchocerciasis  It is also used for scabies, lice.  Filariasis ( it is microfilaricidal ).

53. Adverse Effects  Fatigue,dizziness, GI disturbance  Killing of microfilaria result in a Mazotti reaction ( fever, headache, dizziness, somnolence, hypotension, tachycardia, peripheral edema……).  Corneal opacities & other eye lesions.

54. Contraindications & Cautions  Concomitant use with other drugs that enhance GABA e.g Barbiturates, bnzodiazepines, valproic acid.  pregnancy  Meningitis  Children under 5 years of age.

55. BITHIONOL  Drug of choice for the treatment of fascioliasis ( sheep liver fluke)  Pharmacokinetics:  It is orally administered and excreted in urine.

56. Adverse Effects  GI disturbance  Dizziness, headache  Skin rashes, urticaria, Leucopenia  Contraindications and precautions:  Hepatitis, leucopenia  Used with caution in children under 8 years of age.