13
Anthelmintic agents
Learning objectives
Upon completion of this chapter, you should be able to:
1.
List the common worms that cause disease in humans.
2.
Describe the therapeutic actions, indications, pharmacokinetics, contraindications, most common adverse
reactions and important drug–drug interactions associated with the anthelmintics.
3.
Discuss the use of anthelmintics across the lifespan.
4.
Compare and contrast the prototype drug mebendazole with other anthelmintics.
5.
Outline the care considerations, including important teaching points to stress, for people receiving an
anthelmintic.
Glossary of key terms
Ascaris
:
the most prevalent helminthic infection; fertilised roundworm eggs are ingested, which hatch in the small intestine and then
make their way to the lungs, where they may cause cough, fever and other signs of a pulmonary infiltrate
cestode:
tapeworm with a head and segmented body parts that is capable of growing to several metres in the human intestine
filariasis:
infection of the blood and tissues of healthy individuals by worm embryos or filariae
helminth:
worm that can cause disease by invading the human body
hookworms:
worms that attach themselves to the small intestine of infected individuals, where they suck blood from the walls of the
intestine, damaging the intestinal wall and leading to severe anaemia with lethargy, weakness and fatigue
nematode:
roundworms such as the commonly encountered pinworm, whipworm, threadworm,
Ascaris
or hookworm that cause a
common helminthic infection in humans; can cause intestinal obstruction as the adult worms clog the intestinal lumen or severe
pneumonia when the larvae migrate to the lungs and form a pulmonary infiltrate
pinworm:
nematode that causes a common helminthic infection in humans; lives in the intestine and causes anal and possible vaginal
irritation and itching
platyhelminth:
flatworms, including the cestodes or tapeworms; a worm that can live in the human intestine or can invade other
human tissues (flukes)
schistosomiasis:
infection with a blood fluke that is carried by a snail; it poses a common problem in tropical countries, where the snail
is the intermediary in the life cycle of the worm; larvae burrow into the skin in fresh water and migrate throughout the human body,
causing a rash and then symptoms of diarrhoea, and liver and brain inflammation
threadworm:
pervasive nematode that can send larvae into the lungs, liver and CNS; can cause severe pneumonia or liver abscess
trichinosis:
disease that results from ingestion of encysted roundworm larvae in undercooked pork; larvae migrate throughout the
body to invade muscles, nerves and other tissues; can cause pneumonia, heart failure and encephalitis
whipworm:
worm that attaches itself to the intestinal mucosa and sucks blood; may cause severe anaemia and disintegration of the
intestinal mucosa
Test your current knowledge of anthelmintic agents with a PrepU Practice Quiz!
ANTHELMINTICS
albendazole
ivermectin
mebendazole
praziquantel
pyrantel
