Anti-parasitic drugs Flashcards
three major types of worms
- nematodes
- trematodes or flukes
- cestodes or tapeworms
this class of worms includes:
- roundworms
- threadworms
- pinworms
- hookworms
Nematodes
flukes include __________in man and ______ _____ and ____in ruminants
- schistosoma
- fasciola hepatica and gigantica
Taenia and Diphydium species belong to this group of worms
cestodes/tapeworms
the head of the tapeworm is called the
scolex
humans get tapeworms from
ingesting food that has been contaminated with tapeworms, often food is undercooked or eaten rare
Human helminths include
- Ascaris
- Trichuris
- Stronglygloides
- Enterobius
- Ancylostroma
the common name for ascaris
roundworm
scientific name for whipworm
trichuris
common name for stronglyloides
threadworms
scientific name for pinworms
enterobius
common name for anycyclostroma
hookworm
Toxocara canis is found in this species and when transferred to man can cause the following four medical conditions:
Dog
- asthma - lung larvae
- epilepsy - brain larvae
- hepatitis - liver larvae
- blindness - larvae constrict blood vessels of eyes
Ideal anti-helmintics have these 7 properties
- destroy all species of worms
- are effective against all stages of the lifecycle
- are effective in all sites of the body
- do not cause worms to develop resistance
- are non-toxic to animal
- do not have long drug residues such that animal is removed from milking for too long
- cost effective
Classes of anti-nematodal drugs (8)
- cyanine dyes
- piperazine & diethylcarbamazine
- biphenium
- imidazole
- pyimidines
- organophosphates
- avermectins
- benzimidazoles
these antihelmintics are effective against lungworms
- Diethylcarbamazine
- Levamisole
- Avermectins
- thiabendazole
which antihelmentic is good for heartworm
selemectin (Ivermectin)
what is the mechanism of action of diethylcarbamazine and levamisole
- sensitizes lungworms to body’s immune system
- worms destroyed by macrophage
what is the mechanism of action of many antihelmintics
depolarization of muscle causing spastic paralysis
in fasciola hepatica the adult flukes live in which part of the body
bile duct
Antitrematodal drugs include these 4 classes
- Salicylanilides
- substituted Phenols
- benzimidazole
- Diamphetide
which of the antitrematodals has the best effectiveness against immature flukes
diamphetide
what is the mechanism of action of salicylandilides and substitued phenols
- decouple oxidative phosphorylation
- energy is produced in the form of heat
- worm dies due to lack of nrg and hyperthermia
what is an important characteristic of anti-trematodal drugs
they must be well absorbed in the GIT in order to be taken up in the liver and excreted in the bile
