anti helmentics, actions, uses, adverse effects

Anti helmentics

1. ANTI HELMENTIC DRUGS DR. JYOSHNA SALLA 1

2. H e l m e n t h s : Nemathelmenths : Round body worms Intestinal Nematodes S o m a tic N e m a t o de s Platyhelmenths : Flat body worms T r e m a t o d s : F l u k e s Cestodes : Tapeworm 2

3. Nemathelmenths: Intestinal nematodes: Round worm – A sc aris lu m bro c oid e s W hip w orm – T ri c h u ris t ri c hura Thread worm – S t ron g y loid e s s t er c or a lis Hook worm – An ky lo s t o m a duodenale Pin worm –Enterobius vermicularis Pork worm- Trichinella spiralis Somatic Nematodes: L y m pha t ic f ilarial w or m ( wucheraria bancrofti) O cc uloder m a f ilarial w orm ( on c o c er c a v ol v ulu s ) Guinea w orm ( D ra c un c ulus m edi n en s e s ) 3

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5. P l a t y h e l m e n t h s : Trematodes(Flukes) Blood fluke (schistosoma he m a t o b i u m ) Liver fluke (Fasciola hepatica) Intestinal fluke (Fasciolopsis Buski) Lung fluke (paragonimus westerme nii) Cestodes(Tapeworm) Pork tapeworm(T. solium) Beef t a p ew o r m ( T . s a g in a t a ) Dwarf tapeworm( Hymenolepis nana) Fish tapeworm( D i p h y ll o b o t r iu m l a tu m ) 5

6. C o mm o n i n d e v e l o p i n g c o un t r i es h a v i n g open defecation issues Worms cause: Depriving host of food Cause blood loss Injury to organs Intestinal or lymphatic obstructions 6

7. Anti Helmentic Drugs : Drugs used t o r e du ce / e r a d i c a t e no . o f h e l me n ti c parasites in the body. 7 Vermicides – kills the worm Vermifuge – expels the worm

8. Choice of drug depends on: T yp e o f i n f e c t i o n Efficacy Side effects Dose regimen 8

9. 9 C L A SS I F I C A T I O N ( b a sed o n M O A ) Drugs bind to beta tubulin of parasite: Benzimidazoles ( Mebendazole, Albendazole, Triclabendazole) Drugs causing spastic paralysis of worms : Nn receptor agonist- Pyrantel pamoate, Levamisole Drugs causing flaccid paralysis of worms: GABAa receptors agonist- opens Cl- channel- Piperazine, Ivermectin Drugs causing Ca+ influx - Prazoquantal Drug causing uncoupling of oxidative phosphorylation : Bethionol & Niclosamide Drugs altering microfilarial membrane & increase phagocytosis – DEC (diethyl carbamazine)

10. 10 Me b en d a z o le : Benzimidazole introduced in 1972 Broad spectrum 1st line drug for round worm, hook worm, pin worm, whip worm infection Gives approx 100% cure rate or decrease in egg count Expels Trichinella from intestines but cant kill migrated larvae Immobilizing & lethal action on worm is slow

11. 11 Me b en d a z o le : MOA : drugs bind to beta tubule of parasite & inhibit polymerisation & synthesis of micro tubules Higher affinity (400 times) more than to parasite than humans. Decrease in microtubule----- decrease in multiple metabolic activity parasite Decrease glucose uptake, & depletes glycogen storage

12. 12 Me b en d a z o le : Dose – 100mg BD for 3 days a/e : we lltolerated Nausea, vomitings, abdominal pain, diarrhea on heavy infestations. Large dose- headache,dizziness, loss of hair & granulocytopenia

13. 13 Albendazole Broad spectrum Advantages : Better tolerated Single dose effectiveness Active metabolite of albendazole achieves a higher conc.

14. 14 Albendazole Pk : Fatty food enhance drug absorption A/e: Nausea, vomitings, diarrhea, abdominal pain Teratogenic in animals , not given in pregnancy

15. 15 Albendazole Uses; DOC – roundworm, hookworm, pinworm S i n g l e d o s e – 400 m g , d o s e r e p e a t ed a f t er 2 w e e k s t o prevent re infection. T r i c h i n o s i s , t a p e w o r m , s t r a n g y l o i d es - 400 m g, 3 d a y s N e u r o c y s t i c e r c o s i s - d o c , 400 m g BD H y d a t i d c y s t - d o c , 400 m g, B D f o r 4 w ee k s , r e p e a t a f t er 2 w e e k s i f n e e d ed Filariasis

16. 16 Pyrantel pamoate: Effective againt roundworm, hookworm, pinworm Moa : stimilates nicitinic cholinergic receptor.......persistent depolarisation & spastic paralysis.......paralysed worms expelled s/e: Well tolerated Occasional headache, rashes, weakness, dizziness Dose : 10- 15 mg/kg

17. 17 L e v a m is o le : Effective against roundworm & hookworm Well tolerated Effective in single dose immunomodulater

18. 18 Niclosamide: Effective against most tapeworms Dead tapeworm segments are partly digested & ova of t. solium thus sometimes reach various organs causing visceral cystivercosis Well tolerated Abdominal discomfort, rarely pruritis, rashes Doc – t.solium, t. saginata, h. nana

19. 19 Praziquantel : Effective against schistosomiasis, most trematodes, cestodes Single oral dose Moa : increase cell membrane permiability to CA+ …....contraction......paralysis & worms are expelled. a/e: Gi disturbances, headache, dizziness, drowsiness

20. 20 Praziquantel : Uses: Schistosomiasis- DOC Tapeworm – single dose very effective ( 10mg/ kg)

21. 21 D ec Doc – Filariasis Mo a : i mm o b ilis e m i c r o f il a r i a ....d i s p l a c e m e n t i n tissues......alter surface structure making them more susceptable to host defence mechnism Uses : Filariasis – 2mg/kg tid for 21 days

22. 22 Ivermectin : Semisynthetic analog of avermectin B Obtained from – streptomyces avermitilis Effective against – many nematodes, arthropods, filariae that infect animals & human beings Very effective against microfilaria od onchocerca volvulus Microfilaricidal- blocks release of microfilaria from uterus of adult worm

23. 23 Ivermectin : Moa : paralysing worm by binding to gaba gated cl channels......enhance gaba activity a/e: Well telerated Nausea, vomitings allergic reaction causing hypersensitive reaction( mazotti reaction)

24. 24 Ivermectin : Uses: Doc – onchocerciasis Lymphatic filariasis Single dose, 400mg/kg + 400mg albendazole- once year.......mass chemotherapy for lymphatic filariasis Strongylopidiasis- 200mg/kg dose curative

25. Thank you 25 This Photo by Unknown author is licensed under CC BY-NC .