Anthelmintic drugs sam
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Transcript of Anthelmintic drugs sam
Presented by:Samya Sayantan (121-29-381)Batch: 7th
Sec: ADepartment of PharmacyDaffodil International University
Presentation onAnthelmintic Drugs
Anthelmintics or antihelminthics are drugs that expel parasitic worms(helminths) from the body by either stunning or killing them.
They may also be called vermifuges (stunning) or vermicides (killing).
There has three major group of helminthes -the nematodes, trematodes and cestodes
Anthelmintic:
Mebendazole:Mebendazole is a synthetic benzimidazole
compound is effective against a wide spectrum of nematodes.
Mebendazole a medicine used to treat infections by worms.
This including pinworms, roundworms, tapeworms, hookworms, and whipworms.
Drugs for Nematodes
Binds with β-tubulin and inhibits microtubules polymerization.
Blocks glucose and other nutrients uptake.Resulting in the gradual immobilization
and eventual death of the helminthes.
Mechanism of action:
In heavy infestation casesDiarrhoeaNauseaAbdominal pain In high doseGranulocytopeniaAllergic reaction
Adverse Effect
Pyrantel pamoate along with mebendazole is effective in the treatment caused by roundworm, pinworm & hookworm.
It is poorly absorbed orally in the intestinal tract.
It is inactive against trichuris and other worms
Pyrantel pamoate:
Causes the release of acetylcholine and inhibits cholinesterase,
Acts as a depolarizing neuromuscular blocker,Paralyzing the helminthes,This has the result of causing the worm to
"lose its grip" on the intestinal wall and be passed out of the system by natural process.
Mechanism of action:
CNS: dizziness, headache, insomniaDermatologic: rashGIT: anorexia, nausea, abdominal cramps,
diarrheaNeuromuscular & skeletal: weakness
Adverse effect:
First benzamidazole polyanthelmintics.Chelating agents and form stable complexes
with metals including iron but does not bind with calcium.
Completely metabolized in liver.
Thiabendazole:
The precise mode of action of thiabendazole on the parasite is unknown, but it most likely inhibits the helminth-specific enzyme fumarate reductase.
Thereby inhibiting the citric acid cycle, mitochondrial respiration and subsequent production of ATP, ultimately leading to helminth's death.
Mechanism of action:
GI disturbanceIrreversible liver failureFatal Stevens-Johnson syndrome dizziness anorexia
Adverse effect:
Potent semisynthetic derivativeObtain from Streptomyces avermitilsDrugs of choice of strongyloidiasis,
filariasis, ascariasis, enterobiasis and some parasitic skin diseases including scabies
Ivermectin:
Acts on the parasites glutamate-gated Cl- channel receptors.
Chloride influx increased, hyper polarization occurs , resulting in paralysis of the worm.
Mechanism of action:
Fatigue, dizziness, GI disturbance
Nausea
Abdominal pain
Pruritis
Adverse effect:
Diethyl carbamazine is used as an anthelmintic drug in the treatment of filariasis because of its ability to immobilize microfilarae and render them susceptible to host defencse mechanism.
Diethyl carbamazine:
Immobilizes microfilariae and alters their
surface structure
displacing them from tissues & making them
susceptible to destruction by host defense
mechanism
It has immunosuppressive effects
Mechanism of action:
Fever, maliseheadache, GI disturbance, cough. Chest, muscle, joint pain
LeucocytosisRetinal hemorrhageIt is not teratogenic
Adverse Effect:
Praziquantel:Novel anthelmintic with wide range of action.Praziquantel is a drug which effective against
schistosomiasis and trematodes and cestodes.
Drugs for Tremadoes
Rapidly taken up by worms.Leakage of intracellular Ca++ causing
paralysis.Worms lose grip on intestinal wall including
tissues and veins.Acts against all stages of worm including
larvae.
Mechanism of action:
Bitter in tasteNauseaAbdominal painHeadacheDizziness and sedationRashes, fever, itching and body pain
Adverse Effect:
Niclosamide:Niclosamide is the drug of choice for most
cestode infections.It safe during pregnancy.
Drugs for Cestodes
Inhibition of oxidative phosphorylation in mitochondria
Interference of anaerobic generation of ATP by tapeworm.
Injured worms are digested or expelled (purgation)
Mechanism of action:
Well toleratedNo systemic toxicityMinor abdominal symptomsMalaise PruritisDiarrhea
Adverse Effect:
Congener of Mebendazole.One dose treatment has cure rate in
ascariasis, hookworm, enterobius.It is also used in the treatment of cestodal
infestations such as cysticercosis and hydatid disease.
Albendazole:
Binds with β-tubulin and inhibits microtubules polymerization.
Blocks glucose and other nutrients uptake.Intestinal parasites are immobilized and die
slowly.
Mechanism of action:
Well toleratedGI side effectsDizzinessProlonged used in hydatid and
cysticercosis- headache, fever, alopecia, neutropenia, jaundice.
Adverse Effect:
Pinworm disease:Causative agent: Enterobius vermicularisPruritus ani occurs with white worms visible in
stools or perianal regionTherapay: Mebedazole or Pyantel pamoate.
Common Nematodes Infections
Causative agent: Ascaris lumbricoidesIngested larvae grow in the intestineCausing abdominal symptoms including
intestinal obstractionRoundworms may pass to blood and infect
the lungs.Therapy: Pyrantel pamoate or Mebendazole
Roundworm disease:
Causative agents: Trichinella spiralisUsually caused by consumption of
insufficiently cooked meat, especially porkTherapy: Thiabendazole (only in the early
stages of disease
Trichinosis disease:
Causative agents: Ancylostoma duodenale (old world), Necator americanus (new world)
Worm attaches to the intestinal mucosa, causing anorexia and chronic intestinal blood loss that leads to anemia.
Therapy: Pyrantel pamoate or Mebendazole
Hookworm disease:
Paragonimiasis: Causative agent: Paragonimus westermani
(lung fluke). The organisms move from the GI tract to
the lung which is the primary site of damage
Paragonimiasis is transmitted by eating raw crab
Diagnosed by identifying eggs in the sputum & stool.
Therapy: Praziquantel
Common Trematodes Infections
Causative agent: Clonorchis sinensis (oriental liver fluke)
The primary site of infection is the biliary tract where the resulting inflamatory response can cause fibrosis & hyperplasia
Transmitted by eating raw freshwater fish.Diagnosed by indentifying eggs in the stoolTherapy: Praziquantel
Clonorchiasis:
Echinococcosis:Causative agent: Echinococcus granulosusInfection produces large hydatid cysts in the
liver, lung and brain.Sheep often serve as an intermediate.Diagnosed by CT scan or biopsy of infected
tissue and is treated by surgical excision of cysts.
Therapy: Albendazole
Common Cestodes Infections
Causative agent: Taenia solium larvae Infection produces cysticerci in brain and
eyes.Cysticercosis is diagnosed by CT scan or
biopsy.Therapy: Praziquantel, Albendazole or
Surgery
Cysticercosis: