1 / 19

Anthelminthic

Anthelminthic. Kaukab Azim, MBBS, PhD Modified by :Israa. Commonly encountered nematode (roundworm) infections . Onchocerciasis (river blindness) Enterobiasis (pinworm) Ascariasis (roundworm) Filariasis Trichuriasis (whipworm disease ) Hookworm ( ancylostoma duodanale )

wind
Download Presentation

Anthelminthic

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Anthelminthic Kaukab Azim, MBBS, PhD Modified by :Israa

  2. Commonly encountered nematode (roundworm) infections • Onchocerciasis (river blindness) • Enterobiasis (pinworm) • Ascariasis(roundworm) • Filariasis • Trichuriasis (whipworm disease ) • Hookworm (ancylostomaduodanale) • Strongyloidiasis (threadworm)

  3. Commonly encounterdtrematode (Flukes) infections • Schistosomiasis

  4. Commonly encounterdcestode (Tapeworms) infections • Echinococosis (hydatid disease). • Taeniasis • Cysticercosis

  5. Drugs • BenzimidazolesMebendazoleAlbendazoleThiabendazole • Pyrantelpamoate / Oxantelpamoate • Ivermectin • Diethylcarbamazine (table salt) • Praziquantel

  6. 1. Benzimidazole: Mebendazole Mechanism Of Action: • Inhibits polymerization of tubulin protein by binding to β-tubulin of intestinal & tegumental cells of worm • Also inhibits fumaratereductaseimportant in anaerobic respiration. • Loss of cytoplasmic microtubules leads to loss of up-take of microtubule dependent glucose & depletion of glycogen stores; no glucose no ATP; no oxidation-phosphorylation in mitochondria • Result: No energy, no mobility, death of worm

  7. Mebendazole • Low bioavailability due to poor absorption and due to first pass effect • Co-administration with cimetidine increases mebendazole plasma levels • Decrease dose in liver impairment • Metabolites are active • Contraindicated in pregnancy due to teratogenicity & embryotoxicity in animals • USES: • Effective against 5 nematodes Pin, Round, Whip and hook worms (Necatoramericanusand Ancylostomaduodenale)

  8. 2. PyrantelPamoate • USE: • For pin worm, round worm & hook worm • Oxantelpamoate (1dose) for Trichuriasis • MOA: • Depolarizing neuromuscular blockers, induce marked persistent activation of nicotinic (Ach) receptors of worm; open the cationic channels resulting in irreversible, spastic paralysis of worm; • it also inhibits cholinesterases • Low absorption (>85% passes in feces unaltered) • Safe for pregnant woman

  9. 3. Ivermectin(Nippon Y. Zasshi, 2003 & Gyatt H, De S. N Bundy,1997 May) • A semisynthetic anthelmintic • MOA: • Binds selectively and with strong affinity to GABA or glutamate-gated chloride ion channels in invertebrate nerve and muscle cells • Binding leads to Hyperpolarization of cell membrane • due to influx of chloride ions (glutamate) • due to GABA (direct release) & its receptor stimulation • Result: Paralysis of muscles & death of parasite

  10. Ivermectin • 93% plasma protein-bounded • Excretion via GI route only • Poor CSF distribution • P-glycoprotein efflux pump • Resistance: Widespread use in sheep & cattle

  11. Ivermectin Uses • Strongyloidiasis • Elephantiasis (mass treatment) • Onchocercus volvulus (DOC) • Cutaneous larva migrans • Scabies

  12. Ivermectin • Adverse effects: not much; minimal in absence of parasitic infection • In filariasis: Fever, myalgia, lightheadedness, malaise & postural hypotension • Mazotti reactionin heavy infection due to dying microfilariae • In onchocerciasis: Skin edema, pruritus & mild eye irritation, headache, dizziness, abdominal pain • In combine onchocerciasis & heavy Loa-loa infection: Encephalopathy, do not use) • Don’t use in trypanosomiasis or meningitis

  13. 4. Diethylcarbamazine • Piperazine derivative • DOC for lymphatic filariasis (adult of W. bancrofti, Brugiamalayi& loasis (best for loasis), tropical pulmonary eosinophilia of W. bancroftiand B. malayi, can be used in visceral larva migrans • MOA: Arachidonic acid metabolism interference • Adjust dose in renal dysfunction • Mazotti reaction in onchocerciasis

  14. 5. Praziquantel • Treatment of cestodes & trematodes • Increases Ca++ influx in tegumental cells causing tetanic contracture & loss of adherence to host’stissue • Food & cimetidine facilitate absorption; • Extensive first pass metabolism • Anticonvulsants in cysticercosis & spasmolytic in abdominal pain

  15. The End

More Related