8.ANTHELMINTIC DRUGS

Anthelmintics or antihelminthics are drugs that expel parasitic worms and other internal parasites from the body by either stunning or killing them and without causing significant damage to the host. They may also be called vermifuges or vermicides.

1. BYBY
Dr. Dr. SAMINATHAN KAYAROHANAMSAMINATHAN KAYAROHANAM
M.PHARM, M.B.A, PhDM.PHARM, M.B.A, PhD
ANTHELMINTIC
DRUGS
1
8

2. 2
NUM CONTENT SLIDE
1 OVERVIEW TO ANTHELMINTIC 4-12
2 NEMATODE (ROUND WORMS) 13-36
3 TERMATODES ( FLUKES ) 37-52
4 CESTODES ( TAPEWORMS) 53-67
5 RELATIVE INCIDENCE OF HELMINTH INFECTIONS
WORLDWIDE
68
6 ANTHELMINTIC DRUGS 69-78
7 CHEMICAL STRUCTURES OF ANTHELMINTIC
DRUGS
79
8CLINICAL USE OF ANTHELMINTIC DRUGS 80

3. 3
3
LEARNING OUTCOME
1. Describe and understand the infectious diseases of
Helminthiases and life cycles.
2.Morphology, Scientific classification and symptom of
NEMATODE (ROUND WORMS), TERMATODES
( FLUKES ) and CESTODES ( TAPEWORMS).
3.Able to list the classification of anthelmintic drugs.
4.Abele to demonstrate the general mechanism of
anthelmintic drugs.
5.Able to understand the anthelmintic drugs available
drugs in the market.

4. Predator. “An organism that eats more than one other
organism (animal) during its life.” Usually larger than prey
(exception: social predators).
Parasite. “An organism that lives at the expense of another
(host), which it does not usually kill.” Usually smaller than
host.
Parasitoid. “A parasite that kills its host.” Usually smaller
than host.
Cleptoparasite. ‘A “thief” parasite, one that consumes the
food stored by another insect in a nest. (Evans, 1984)
Smaller or similar size as host; often closely related.
Hyperparasite. Parasite of a parasite. Usually smaller
than host.
4
1. OVERVIEW TO ANTHELMINTIC
4
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

5. Parasites are usually much smaller than their hosts, they also
do not kill before they eat.
5
1. OVERVIEW TO ANTHELMINTIC
5
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

6. INTRODUCTION TO AMOEBA
Entamoeba histolytica
Amoebic dysentery
Naegleria
primary amoebic
meningoencephalitis
Acanthamoeba
contact lens contaminant
6 Figure 12.18a
•Protozoa with no truly defined shape
•Move and acquire food through the use of pseudopodia
•Found in water sources throughout the world
•Few cause disease
1. OVERVIEW TO ANTHELMINTIC
6
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

7. 7
1. OVERVIEW TO ANTHELMINTIC
The helminths comprise two major groups of multicellular
worms that evolved from a common ancestor some 600 million
years ago and diverged into two rather different groups.
The nemathelminths (nematodes, roundworms) and the
platyhelminths (flatworms).
The latter group is subdivided into the trematodes (flukes) and
the cestodes (tapeworms).
Almost 350 species of helminths have been found in humans,
and most colonise the gastrointestinal tract.
Helminths have a complex life cyclecomplex life cycle, often involving several
species. Infection by helminths may occur in many ways, and
poor hygiene is a major contributory factor.
Con
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

8. Many enter by mouth in unpurified drinking water or in badly
cooked meat from infected animals or fish. However, other types can
enter through the skin following a cut, an insect bite or even after
swimming or walking on infected soil.
Humans are generally the primary (or definitive) host for helminth
infections, in the sense that they harbour the sexually mature form
that reproduces.
Eggs or larvae then pass out of the body and infect the secondary Eggs or larvae then pass out of the body and infect the secondary
(intermediate) host. In some cases, the eggs or larvae may persist in (intermediate) host. In some cases, the eggs or larvae may persist in
the human host and become the human host and become encystedencysted, covered with granulation , covered with granulation
tissue, giving rise to tissue, giving rise to cysticercosiscysticercosis. This is characterised by encysted . This is characterised by encysted
larvae in the muscles and the viscera or, more seriously, in the eye or larvae in the muscles and the viscera or, more seriously, in the eye or
the brainthe brain.
 Approximately 20 helminth species are considered to be clinically
significant, and these fall into two main categories-those in which the
worm lives in the host's alimentary canal, and those in which the
worm lives in other tissues of the host's body
8
1. OVERVIEW TO ANTHELMINTIC
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

9. CLASSIFICATION OF HELMINTHES: THEY ARE TWO PHYLA
 CLASS: NEMATODES (ROUND  WORMS)
 I) Intestinal Nematodes:   1) Round worms as Ascaris. 2) Hookworms as
Ancylostoma. 3) Pinworms as Oxyuris. 4) Whipworms as Trichuris.
5) Thread worms as Strongyloids. 6) Enterobius Vermicularis.
II) Tissue Nematodes:Filaria.
Phylum: Platyhelminthes ( flatworms)
CLASS: TERMATODES ( FLUKES )  
1) Liver flukes: Fasciola Hepatica. Fasciola Gigantica
2) Blood flukes: Schistosoma haematobium. Schistosoma mansoni.
3) Intestinal flukes: Heterophyes heterophyes.
CLASS: CESTODES ( TAPEWORMS )  
Beef tapeworm:Taenia saginata.
Pork tapeworm:Taenia solium.
Dwarf tapeworm:Hymenolepis nana.9
1. OVERVIEW TO ANTHELMINTIC
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

10. 10
INFECTIOUS DISEASES - HELMINTHIASES
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

11. 11
INFECTIOUS DISEASES - HELMINTHIASES
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

12. The nematodes or roundworms constitute
the phylum Nematoda.

Nematode species can be difficult to
distinguish, and although over 25,000 25,000
have been described, of which more than
half are parasitic.
total number of nematode species has
been estimated to be about 1 million.
Nematodes have tubular digestive
systems with openings at both ends.
The fertilized female can lay about
200,000 eggs per day.200,000 eggs per day. Eggs require
oxygen and moisture to embryona
12
NEMATODES (ROUND WORMS)
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

13. 13
Nematodes comprise the group of organisms containing the
largest number of helminth parasites of humans.
Range in size, many are very small few millimeters but some
may be up to a meter in length.
“Largest Nematode measured 9 meters long and 2.5 cm in
diameter, found as parasite in a Sperm Whale’s placenta”.
They are unsegmented, bilaterally symmetrical, and exhibit great
variation in their life cycles. Generally, they are long-lived (1-30+
years).
some can have both free-living and parasitic stages in their life
cycle.
Adult Looks like an earthworm
Female (20-35 cm);
 Male (12-30 cm)
3 lips which carry minute teeth
2. NEMATODE (ROUND WORMS)
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

14. 2. NEMATODE ( ROUND WORMS)
THE INTESTINAL
NEMATODES
2.1. Ascaris
2.2 Hook worms
2.3 Pin worm
2.4 Whip worm
THE BLOOD- AND TISSUE
DWELLING NEMATODES
2.5 The filaria
2.6 Trichinella
The larvae initially burrow into the mucosa, penetrate blood vessels and
appear as second stage larvae in the liver within six hours post-
infection.
Here they remain for several days and develop into third stage larvae,
L
3
. These larvae then migrate to the heart and are carried to the lungs
via the pulmonary arteries, arriving within four to seven days.
From there they break out of the capillaries into the alveoli and finally
work their way up the trachea to the pharynx and reach the small
intestine on the 8th or 10th day post-infection.
14Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

15. Most diagnoses are made by
identifying the appearance of the worm
or eggs in feces.
 Due to the large quantity of eggs
laid, physicians can diagnose using
only one or two fecal smears.
Infections can be treated with drugs
called ascaricides.
The treatment of choice is
MEBENDAZOLE . The drug
functions by binding to tubulin in the
worms' intestinal cells and body-wall
muscles. Nitazoxanide and ivermectin
can also be used
15
2.1 ASCARIS
(Ascaris lumbricoides)
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

16. 2.1 ASCARIS(Ascaris lumbricoides)
16 Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

17. 2.1 ASCARIS(Ascaris lumbricoides)
17 Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

18. 18
2.1 ASCARIS lumbricoides is the giant roundworm of humans, growing to a
length of up to 35 cm. It is one of several species of Ascaris. An ascarid
nematode of the phylum Nematoda, it is the largest and most common
parasitic worm in humans.
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

19. 19
The most common treatment for
hookworm is benzimidazoles,
specifically ALBENDAZOLE and
MEBENDAZOLE
2.2 HOOK WORMS
Hookworm is a parasitic nematode that lives in
the small intestine of its host, which may be
a mammal such as a dog, cat, or human. Three
species of hookworms commonly infect
humans:
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

20. 20
2.2 HOOK WORMS
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

21. 21
Ancylostoma duodenale, Necator
americanus and Strongyloides
stercoralis. A.
2.2 HOOK WORMS LIFE CYCLE
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

22. 22
Strongyloidiasis is a human parasitic disease caused by the 
nematode (roundworm)  called Strongyloides stercoralis,  or 
sometimesS. fülleborni which is a type of helminth. 
It belongs to a group of nematodes called hookworms. This 
intestinal worm can cause a number of symptoms in people, 
principally  skin  symptoms, abdominal pain, diarrhea and 
weight loss. 
The diagnosis is made by blood and stool tests. The drug 
IVERMECTIN is  widely  used  in  the  treatment  of 
strongyloidiasis
2.3 STRONGYLOIDIASIS
Frequently asymptomatic. Gastrointestinal system symptoms
 include abdominal pain and diarrhea. Pulmonarysymptoms 
(including Löffler's syndrome) can occur during pulmonary 
migration of the filariform larvae.
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

23. 23
2.3 STRONGYLOIDIASIS
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

24. 24
The pinworm (genus Enterobius), also 
known as threadworm (in the United 
Kingdom and Australia) or seatworm, is a 
parasitic worm.
 It is a nematode(roundworm) and a common 
intestinal parasite or helminth, especially in 
humans.
 The medical condition associated with 
pinworm infestation is known as enterobiasis
 (a type of helminthiasis).
 THE CHIEF SYMPTOM IS ITCHING IN THE ANAL
AREA.
 ALBENDAZOLE or 
MEBENDAZOLE  is the first-line 
treatment of pinworm infection.
 PYRANTEL PAMOATE  is 
alternative.
2.4. PIN WORM
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

25. 25
2.4. PIN WORM
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

26. The pinworm (genus EnterobiusEnterobius), also known as threadworm (in the 
United Kingdom and Australia) or seatworm, is a parasitic worm.
26
2.4. PIN WORM LIFE CYCLE
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

27. The human whipworm (Trichuris
trichiura or Trichocephalus trichiuris) is a 
round worm (a type of helminth) that causes 
trichuriasis (a type of helminthiasiswhich is one of 
the neglected tropical diseases) when it infects a 
human large intestine. 
It is commonly known as the whipworm which refers 
to the shape of the worm; it looks like a whip with 
wider "handles" at the posterior end.
Symptoms
Bloody diarrhea
Iron-deficiency anemia
Fecal incontinence (during sleep)
Rectal prolapse
Treatment
MEBENDAZOLE taken by mouth for 3 days is 
commonly prescribed when the infection causes 
symptoms. ALBENDAZOLE OR
IVERMECTIN may sometimes be used.
2.5. WHIP WORM
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

28. 2.5. WHIP WORM
28
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

29. 29
2.5. WHIP
WORM
(TRICHIURA)
LIFE CYCLE
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

30. The Filarioidea are a superfamily of 
nematodes (roundworms).
The members of this superfamily are known 
as filarial worms.
 Infections with parasitic filarial worms 
cause filariasis. 
30
People with the disease can suffer 
from lymphedema and elephantiasis and in men, swelling of the 
scrotum, called hydrocele. Lymphatic filariasis is a leading cause 
of permanent disability worldwide.
2.6. FILARIA
standard-dose 
ALBENDAZOLE-IVERMECTIN  
treatment
Surgery
Lymphatic filariasis
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

31. 2.7. FILARIA
31
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

32. 32
2.5. FILARIA LIFE CYCLE
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

33. 33
SYMPTOMS
Diarrhea
Abdominal cramps
Tiredness
Muscle aches and pains
High fever
Swelling in your eyes and face
Eye infection 
(conjunctivitis, or pink eye)
Rashes
Trichinosis or trichiniasis, is a parasitic disease caused by 
eating raw or undercooked pork or wild game infected with the 
larvae of a species of roundworm Trichinella spiralis, commonly 
called the trichina worm. There are eight Trichinella species
PRIMARY TREATMENT
Early administration of 
anthelmintics, such as 
MEBENDAZOLE or 
ALBENDAZOLE ,
Secondary treatment
After infection, steroids, such 
as prednisone may be used to 
relieve muscle pain associated 
with larval migration.
2.8. TRICHINELLA
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

34. 2.8. TRICHINELLA
34
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

35. 35
2.8. TRICHINELLA
LIFE CYCLE
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

36. 36
THERAPY FOR NEMATODE INFECTIONS
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

37. The trematodes (or flukes) are leaf shaped 
with an outer cover called the tegument 
which may be smooth or spiny. 
There are two suckers or attachment 
organs, an anterior oral sucker and a 
posterior ventral sucker.  
The suckers form a characteristic feature 
of the group, from which the name 
Trematode is derived from the Greek word Trematode is derived from the Greek word 
for “holefor “hole.” They can occur in a variety of host 
environments, with the majority being 
endoparasites but some are found to be 
ectoparasitic.
Most trematodes are hermaphroditic and 
most of the body consists of reproductive 
organs and their associated structures. 
 The digestive system is well developed; 
they generally feed on intestinal debris, 
blood, mucus and other tissues, depending 
on the host environment.
3. TERMATODES ( FLUKES )
37Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

38. Fasciolosis the common liver fluke) and 
Fasciola gigantica. 
Both species overlap in many areas of Africa 
and Asia.
host range is very broad and including 
humans. 
 life cycle includesfreshwater snails as an 
intermediate host of the parasite.
Recently, worldwide losses in animal 
productivity due to fasciolosis were 
conservatively estimated at over US$3.2 billion 
per annum.
In addition, fasciolosis is now recognized as 
an emerging human disease: the 
World Health Organization (WHO) has 
estimated that 2.4 million people are infected 
with Fasciola, and a further 180 million are at 
risk of infection. 
38
3.1. FASCIOLA
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

39. 39
The Liver Fluke Infection: FascioliasisThe Liver Fluke Infection: Fascioliasis
Adult fluke of
a Fasciola Trematode. Their
morphology shows a large
leaf-shape about 2–3cm long
with two suckers, an oral and
a ventral one.
3.1. FASCIOLA SPECIES
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

40. GEOGRAPHIC
DISTRIBUTION
RESERVOIR
HOSTS
HOST
LOCATION
OF ADULT IN
SIZE OF OVA
Fasciola
hepatica
Cosmopolitan Sheep Bile Ducts
130-150µm by 
63-90µm
Fasciola
gigantica
Africa, the 
Orient and 
Hawaiian 
Islands
Camels, 
Cattle and 
Water Buffalo
Bile Ducts
160–190µm by 
70-90µm
Fasciolopsis
buski
Far-East and 
Indian Sub-
continent
Pigs, Dogs 
and Rabbits 
Human
Intestine
130–140µm by 
80-85µm
Echinostoma
species
South East Asia 
and Japan
Variety of 
Mammals
Intestine
88–116µm by 
58-69µm
40
3.1. FASCIOLA SPECIES
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

41. 41
3.1. FASCIOLA SPECIES
TRICLABENDAZOLE  (Egaten) in dose 10–12 mg/kg is the drug 
of choice in human fasciolosis. PRAZIQUANTEL treatment is 
ineffective.
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

42. 3.2. CLONORCHIS SINENSIS
Clonorchis sinensis, also known as the Chinese 
(aka Oriental) liver fluke is a narrow elongate liver 
fluke found in the Far East, mainly Japan, Korea, 
China, Taiwan and Vietnam.
Three main species which commonly infect man.
 All members of this group are parasites of fish-
eating mammals, particularly in Asia and Europe. 
Man is the definitive hosts and water snails and fish 
are the intermediate hosts.
Infections can be easily avoided by man not eating 
raw fish since this is the only way that infection can 
be passed on.
Clonorchis sinensis parasitize  the  biliary  duct  in 
humans  who  become  infected  by  eating  raw  or 
undercooked  fish.   Dogs  and  cats  are  the  most 
important reservoir hosts.
42
Drugs used to treat infestation include triclabendazole,
praziquantel, bithionol, albendazole, levamisole and 
mebendazole.However, benzimidazoles are very weak 
as vermicide. PRAZIQUANTEL is the drug of choice.
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

43. 43
3.2. CLONORCHIS SINENSIS LIFE CYCLE
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

44. 3.2. CLONORCHIS SINENSIS
44
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

45. Heterophyes
heterophyes
Metagonimus
yokogawai
Opisthorchis
viverrini
Dicrocoelium
dendriticum
Geographic
distribution
Far East Far East Thailand Far East
Location of adult
in host
Small intestineSmall intestine
Liver and bile
ducts
Liver and bile
ducts
Size of ova
26.5-30mm
by
15-17mm
26.5-30mm
by
15-17mm
26.7mm
by
15mm
38-45mm
by
22-30mm
Shape of ova
Prominent opercular
shoulders Bile
stained
Prominent
opercular
shoulders Bile
stained
Prominent
opercular
shoulders Bile
stained
Dark brown,
thick shelled
and large
operculum
Infection acquired
by
Eating raw or pickled
fish
Eating raw or
pickled fish
Eating raw fresh
water fish
Eating infected
ants
Symptoms
Occasionally diarrhea
and vomiting
Occasionally
diarrhea and
vomiting
Malaise and
right upper
quadrant pain
Biliary and
digestive
45
3.2. LESS COMMON FLUKES THAT ARE KNOWN TO INFECT MAN
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

46. 46
3.2. PARAGONIMUS WESTERMANI
Paragonimus westermani is a lung fluke found in both humans and animals.
The adults are 12µm long and are found in capsules in the lung. The species
sometimes is called the Japanese Lung fluke or Oriental Lung fluke. Human
infections are most common in eastern Asia and in South America.
The symptoms
bad cough,
bronchitis,
and blood in
sputum
(hemoptysis)
PRAZIQUANTEL
is the drug of choice to
treat paragonimiasis.
The recommended
dosage of 75 mg/kg per
day, divided into 3 doses
over 3 days has proven
to eliminate P.
westermani
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

47. 3.3. PARAGONIMUS WESTERMANI
47 Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

48. 48
The Schistosomes are blood
trematodes
They are the only trematodes that live
in the blood stream of warm-blooded
hosts.
Over 200 million people are infected
over at least 75 countries with 500
million or more people exposed to
infection.
With the disease spreading due to
improved water supplies.
3.4. SCHISTOSOMA
Schistosomiasis is treatable using a
single dose of the drug
PRAZIQUANTEL by mouth
annually
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

49. 49
3.4. SCHISTOSOMA
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

50. 50
3.4. SCHISTOSOMA
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

51. 51
3.4. SCHISTOSOMA
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

52. 52
3.5 THERAPY FOR TREMATODE INFECTIONS
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

53. 53
Cestoda (cestoidea) is the name given to a class of parasitic flatworms,
The best-known species are commonly called tapeworms. Cestodes are
all parasitic and their life histories vary, but typically they live in the
digestive tracts of vertebrates as adults, and often in the bodies of other
species of animals as juveniles.
Humans are subject to parasitism by several species of tapeworms if they
eat undercooked meat such as pork (taenia solium), beef (t. Saginata), and
fish (diphyllobothrium spp.), Or if they live in, or eat food prepared in,
conditions of poor hygiene (hymenolepis orechinococcus species).
T. Saginata, the beef tapeworm, can grow up to 20 m (65 ft); the largest
species, the whale tapeworm polygonoporus giganticus, can grow to over
30 m (100 ft).
Discovered in fossil feces (coprolites) of a shark dating to the mid- to late
permian, some 270 million years ago.
4. CESTODES ( TAPEWORMS)
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54. 4. CESTODES
Taenia saginata
Taenia solium
35 mm. Range, 31-
43 mm.
Walnut brown.
Thick, striated shell. Eggs of T.
solium and T. saginata are
indistinguishable and species
identification should be made from
proglottids or scoleces. "Taenia"
spp. should be reported if only eggs
are found.
Hymenolepis nana 47 mm x 37 mm.
Range, 40-60 mm x 30-
50 mm.
Colorless, almost
transparent.
Polar filaments.
Hymenolepis
diminuta*
72 mm. Range, 70-
86 mm x 60-80 mm.
Yellow.
Resembles H. nana but lacks polar
filaments. Poles are rudimentary
and often hard to see.
Dipylidium
caninum*
35-40 mm. Range, 31-
50 mm x 27-48mm.
Colorless.
Eggs are contained in a sac or
capsule which ranges in size from
58mm to 60 mm x 170 mm.
Occasionally capsules are ruptured
and eggs are free.
Diphyllobothrium
latum
66 mm x 44 mm.
Range, 58-76 mm x 40-
51 mm.
Yellow to brown.
Egg resembles hookworm egg but
has a thicker shell and an
operculum
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Taenia saginata commonly known as
the beef tapeworm, It is an
intestinal parasite of cattle and
humans, causing taeniasis (a type of
helminthiasis) in humans.
It is found globally and most
prevalently where cattle are raised
and beef is consumed. It is relatively
common in Africa, some parts of
Eastern Europe, Southeast Asia,
South Asia, and Latin America.

Humans are generally infected as a
result of poor hygiene.
It is typically larger and longer
4.1. TAENIA SAGINATA
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4.1. TAENIA SAGINATA
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4.1. TAENIA TAPEWORMS IN HUMANS
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SYMPTOMS
T. saginata infection is usually asymptomatic, but
heavy infection often results in weight loss,
dizziness, abdominal pain, diarrhea, headaches,
nausea, constipation, chronic indigestion, and loss
of appetite.
TREATMENT
Taenaisis is easily treated with PRAZIQUANTEL (5–
10 mg/kg, single-administration) or NICLOSAMIDE
(adults and children over 6 years: 2 g)
ALBENDAZOLE is also highly effective for treatment of
cattle infection
4.1. TAENIA SAGINATA
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4.1. TAENIA SAGINATA LIFE CYCLE
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4.2. HYMENOLEPIS NANA
Dwarf tapeworm is one of the most
common cestodes (a type of intestinal
worm or helminth) infecting humans,
especially children.
Hymenolepiasis is infestation by one
of two species of tapeworm:
Hymenolepis nana or
Hymenolepis diminuta.
The 2 drugs that have been
described for the treatment of
hymenolepiasis
are PRAZIQUANTEL and
NICLOSAMIDE.
ABDOMINAL DISCOMFORT
DEHYDRATION FROM PROLONGED
DIARRHEA
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4.2. HYMENOLEPIS NANA
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4.2. HYMENOLEPIS NANA
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Diphyllobothrium is a genus of tapeworm which
can cause Diphyllobothriasis in humans through
consumption of raw or undercooked fish.
That infects fish and mammals. D. latum is native
to Scandinavia, western Russia, and North
America,. East Russia.
The salmon tapeworm which has a much larger
range
The standard treatment for
diphyllobothriasis, as well as many other
tapeworm infections is a single dose
of PRAZIQUANTEL, 5–10 mg/kg PO
once for both adults and children. An
alternative treatment is NICLOSAMIDE, 2
g PO once for adults or 50 mg/kg PO
once.
4.3. DIPHYLLOBOTHRIUM
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4.3. DIPHYLLOBOTHRIUM
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4.3. DIPHYLLOBOTHRIUM
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THERAPY FOR CESTODE INFECTIONS
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5. RELATIVE INCIDENCE OF HELMINTH INFECTIONS WORLDWIDE
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6. ANTHELMINTIC DRUGS
roundworms
(flukes) are leaf-
shaped flatworms
tapeworms
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Diethylcarbamazine is used in the treatment of filariasis
because of its ability to immobilize microfilariae and render
them susceptible to host defense mechanisms.
 Combined with albendazole, diethylcarbamazine is effective in
the treatment of Wuchereria bancrofti and Brugia malayi
infections.
It is rapidly absorbed following oral administration with meals
and is excreted primarily in urine.
Symptoms include fever, malaise, rash, myalgias, arthralgias,
and headache, and their severity is related to parasite load.
Most patients have leukocytosis. Antihistamines or steroids
may be given to ameliorate many of the symptoms.
6.1. DIETHYLCARBAMAZINE
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Ivermectin is the drug of choice for the treatment of
onchocerciasis (river blindness) caused by Onchocerca
volvulus and for cutaneous larva migrans and strongyloidiasis.
Ivermectin targets the parasite’s glutamate-gated
chloride channel receptors. Chloride influx is enhanced,
and hyperpolarization occurs, resulting in paralysis of the
worm.
The drug is given orally. It does not cross the blood-brain
barrier and has no pharmacologic effects in the CNS.
Ivermectin is also contraindicated in pregnancy.The killing of
the microfilaria can result in a Mazotti-like reaction (fever,
headache, dizziness, somnolence, and hypotension).
6.2. IVERMECTIN
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Mebendazole a synthetic benzimidazole compound, is
effective against a wide spectrum of nematodes.
 It is a drug of choice in the treatment of infections by
whipworm (Trichuris trichiura), pinworm (Enterobius
vermicularis), hookworms (Necator americanus and
Ancylostoma duodenale), and roundworm (Ascariasis
lumbricoides).
Mebendazole acts by binding to and interfering with
the assembly of the parasites' microtubules and also
by decreasing glucose uptake. Affected parasites are
expelled with the feces.
 Mebendazole is relatively free of toxic effects, although
patients may complain of abdominal pain and diarrhea. It is,
however, contraindicated in pregnant women ,because it has
been shown to be embryotoxic and teratogenic in
experimental animals.
6.3. MEBENDAZOLE
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Pyrantel pamoate along with mebendazole,
is effective in the treatment of infections caused by
roundworms, pinworms, and hookworms.

Pyrantel pamoate is poorly absorbed orally and exerts
its effects in the intestinal tract.
It acts asa depolarizing, neuromuscular-
blocking agent, causing persistent activation of
the parasite’s nicotinic receptors.
The paralyzed worm is then expelled from the host’s
intestinal tract. Adverse effects are mild and include
nausea, vomiting, and diarrhea.
6.4. PYRANTEL PAMOATE
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Thiabendazole another synthetic benzimidazole,is effective against
strongyloidiasis caused by Strongyloides stercoralis (threadworm),
cutaneous larva migrans, and early stages of trichinosis (caused by
Trichinella spiralis;
Thiabendazole, like the other benzimidazoles, affects
microtubular aggregation.
 Although nearly insoluble in water, the drug is readily absorbed on
oral administration.
It is hydroxylated in the liver and excreted in urine. The adverse
effects most often encountered are dizziness, anorexia, nausea, and
vomiting. There have been reports of central nervous system (CNS)
symptomatology.
There have been a number of fatalities among the
cases of erythema multiforme and Stevens-Johnson syndrome
reportedly caused by thiabendazole. Its use is contraindicated during
pregnancy.
6.5. THIABENDAZOLE
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Trematode infections are generally treated with praziquantel. This
drug is an agent of choice for the treatment of all forms of
schistosomiasis and other trematode infections and for cestode
infections like cysticercosis.
Permeability of the cell membrane to calcium is increased,
causing contracture and paralysis of the parasite.
Praziquantel is rapidly absorbed after oral administration and
distributes into the cerebrospinal fluid. High levels occur in bile. The
drug is extensively metabolized oxidatively, resulting in a short half-life.
Common adverse eff ects include drowsiness, dizziness, malaise,
and anorexia as well as gastrointestinal upsets. The drug is not
recommended for pregnant women or nursing mothers. Drug
interactions due to increased metabolism have been reported .
Praziquantel is contraindicated for the treatment of ocular
cysticercosis, because destruction of the organism
in the eye may damage the organ.
6.6. PRAZIQUANTEL
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 Broad spectrum
Drug of choice for treatment of hydatid
disease and cysticercosis.
Used for the treatment of ( intestinal nematodes )
e.g. ascariasis , tricurasis and strongyloidiasis,
pinworm, hookworm
Inhibits microtubule synthesis that
irreversibly impairs glucose uptake , intestinal
parasites are immobilized and die slowly.
 larvicidal in : hydatid ,cysticercosis , ascariasis
and hook worm infections.
 Ovicidal in ascariasis ,hookworm , trichuriasis
6.7. ALBENDAZOLE
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Its primary therapeutic application, however, is in the treatment of
cestodal infestations, such as cysticercosis (caused by Taenia
solium
larvae) and hydatid disease (caused by Echinococcus granulosus).
Albendazole is erratically absorbed after oral administration, but
absorption is enhanced by a high-fat meal.
Albendazole and its metabolites are primarily excreted in urine.
adverse effects are mild and transient and include headache and
nausea. Parasites in the CNS, including headache, vomiting,
hyperthermia, convulsions, and mental changes.
The drug should not be given during Pregnancy or to children
under 2 years of age.
6.7. ALBENDAZOLE
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Niclosamide is the drug of choice for most cestode
(tapeworm) infections.
Its action has been ascribed to inhibition of the
parasite’s mitochondrial phosphorylation of
adenosine diphosphate, which produces usable
energy in the form of adenosine triphosphate.
anaerobic metabolism may also be inhibited.
Alcohol should be avoided within 1 day of
niclosamide.
6.8. NICLOSAMIDE
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80. 8.CLINICAL USE OF ANTHELMINTIC DRUGS
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