Transcript Antihelmintic drugs

Antihelmintic drugs
By
Dr.Mohamed Abd AlMoneim Attia
Antihelmintic drugs
Drugs active
against
nematodes
Diethylcarbamazine
(systemic)
Albendazole
Mebendazole
Pyrantel pamoate
Ivermectin
Drugs active
against trematodes
Drugs active against
cestodes
Niclosamide
Praziquantel
Praziquantel
Metrifonate
Albendazole
oxamnquine
mebendazole
Drugs active against nematodes
 Intestinal nematodes includes:
1-enterobius vermicularis (pinworm)
2-ascaris lumbricoides (roundworm)
3-ancyclostoma & necator species (hookworm)
4-strongyloides stercoralis (threadworm)
 Tissue nematodes: onchocerca,filariasis
pinworm
hookworm
threadworm
Round worm
Albendazole
 Mechanism of action:
block glucose uptake by the parasite leading to
decrease production of energy and
subsequent parasite immobilization
 Uses:
1-treatment of roundworm,pinworm,hookworm
infection
2-alternative treatment of threadworm,filariasis
3-hydatid disease & cysticercosis
 Side effects:
1- short course treatment :has few side effects
2-long course treatments: leucopenia, alopecia
& elevation of liver enzymes
Diethylcarbamazine

Mechanism of action:
Immobilizes microfilaria by unknown
mechanism increase host susceptibility to
attack it.
 Uses:
1. Drug of choice in filarial
infection of the eye (loa loa)
1. Alternate drug in elephantiasis.
 Side effects:
1-headache,malasie,weakness,nausea
2-reaction to dying filaria includes: fever,
rash,ocular damage, joint pain and
lymphangitis
Ivermectin
 Mechanism of action: facilitates GABA
mediated neurotransmission in nematodes
causing immobilization of the parasite,
facilitating its removal by reticuloendothelial
system.
 Uses:
 Drug of choice in treatment of onchocercosis,
and threadworm infection
 Side effects:
Mazzotti reactions(due to killing of microfilaria)
and includes,fever, joint pain, rash
hypotension,tachycardia
Mebendazole
 Mechanism of action:
Inhibit glucose uptake and microtubule
synthesis in nematodes.
 Uses:
Primary drug in roundworm and pinworm
infection
 Side effects:
GIT upsets, alopecia and agranulocytosis in
high dose
Piperazine
 Mechanism of action:
Act as GABA receptor agonist causing paralysis
of the parasite and expelled live by normal
intestinal peristalsis
 Uses: alternate drug in treatment of
roundworm infection.
 Side effects: GIT upsets, teratogenic
Pyrantel pamoate
 Mechanism of action:
Stimulate nicotinic receptor present at the NMJ
of nematode.contraction of the muscle occurs
followed by depolarization induced paralysis.
 Uses:
1- drug of choice for hookworm & roundworm
infection
2-alternate drug in pinworm infection
Side effects: mild GIT upsets
Thiabendazole
 Mechanism of action: like mebendazole
 Uses: alternate drug in threadworm infection
 Side effects: unsafe drug
1-GIT irritation,headache,drowsiness
2-leukopenia,haematuria
3-allergic reaction
Drugs active against trematodes
 Medically important trematodes are:
1-schistosoma species (blood fluke)
2-clonorchis sinesis (liver flukes in southeast
Asia)
3-paragonimus westermani ( lung fluke in
Asia,India)
Praziquantel
 Mechanism of action:
Increase membrane permeability to calcium
causing muscle contraction followed by
paralysis leading to vacuolization and death
of the parasite.
Uses:
1- drug of choice of all trematodes infection
2-one of 2 drugs of choice in cestodes infection
 Side effects:
1-common adverse effects: GIT
upset,headach,malaise,skin rash
2-intracranial hypertension and convulsion if
used in ttt of neurocysticercosis
 Contraindication: ocularcysticercosis
Bithionol
 Uses:
Drug of choice in ttt of fascioliasis ( sheep liver
fluke)
Side effects:
1-common: N/V,headache,phototoxcity
2-less common: protenuria,leucopenia
Drugs active against cestodes
 The 4 important cestodes are:
1-taenia saginata ( beef tapeworm)
2-taenia solium ( pork tapeworm that causes
cysticerci in brain and eye)
3-diphyllobothrium latum ( fish tapeworm)
4-echinococcus granulosus (dog tapeworm that
cause hydatid cysts in lung,liver,and brain)
beef tapeworm
Hydatid cyst in liver
Niclosamide
 Mechanism of action:
Act by activating ATPases
 Uses:
1- 1 of 2 drugs of choice ( with praziquantel) in ttt of
fish,pork,and beef tapeworms infection
2-not effective in cycticercosis (albendazole or
praziquantel is used)
3- not effective in hydatid disease ( albendazole is
used).
 Side effects:
Mild GIT upset, rash headache
Drug for treatment of nematodes
Infecting organism
Ascaris(roundworm)
Drug of choice
Alternative drug
Albendazole,mebendazole,py
rantel pamoate
piperazine
Ancylostoma(hookworm)
Albendazole,mebendazole,
pyrantel pamoate
Strongyloids
stercoralis(threadworm
ivermectin
Albendazole,mebendaz
ole,
Enterobius
vermicularis(pinworm)
filariasis
Mebendazole,pyrantel albendazole
pamoate
diethylcarbamazine
ivermectin
onchocericasis
ivermectin
--------
Drug for treatment of
trematodes
Infecting organism
Drug of choice
Alternative drug
s,.haematobium
praziquantel
metrifonate
s.mansoni
praziquantel
oxamniquine
s.japonicum
praziquantel
Fasciola hepatica
bithional
Fasciolopsis buski
Praziquantel or
niclosamide
Drug for treatment of cestodes
Infecting organism
Drug of choice
t.Saginata (beef tapeworm)
Praziquantel or
niclosamide
t.Solium(pork tapeworm)
Praziquantel or
niclosamide
albendazole
Cysticercosis(pork tapeworm
larval stage)
Diphyllobothrium latium(fish
tapeworm)
Hydatid disease
Praziquantel or
niclosamide
albendazole
Alternative drug
mebendazole
praziquantel
Drugs for leishmaniasis
 Sodium stibogluconate: for all types of
leishmania ( must be given by injection and
cardiotoxic)
 Alternate drugs:
1-Pentamidine for visceral leishmaniasis
2-Fluconazole or metronidazole for cutaneous
lesions
3-Amphotricin B for mucocutaneous lesions
ANTIHELMINTHIC DRUGS
Therapeutic Strategies
 Inhibit muscle contraction
 Inhibit energy metabolism
 Limit distribution of generally toxic drugs
Thank you