1. HELMINTHIC INFECTIONS

2. HELMINTHS
Macroscopic, multiceullar organism
Having their own digestive system, excretory, reproductive and nervous systems

3. INTRODUCTION Humans are the primary hosts.
Most worms produce in human sexually
By producing eggs and larvae.
These pass out of body and infect the secondary host.
Imature forms invade humans via skin or GIT.
Mature to adult worms with characterstic tissue distribution.
GENERAL FEATURES
Worm-like parasites
Outer protective covering- cuticle/integument
Locomotion-muscular contraction & relaxation.
Eggs or larvae produced in enormous numbers.
Inability to multiply in the body of the host.

4. CLASSIFICATION
Based on external and internal morphology of egg, larval, and adult stages & the host organ they inhabit
1)NEMATHELMINTHES
-Cylindrical round worms
a) NEMATODES
Eg: ascaris, ancylostoma, trichuris, strongyloides, enterobius, filariasis, dracunculus.
2) PLATYHELMINTHES
-Flat worms
a) TREMATODES or Flukes :-
Leaf-like.
Eg.Blood flukes(schistosomiasis), fasciola, clonorchis, paragonimus,
b) CESTODES or Tape worms:-
Tape-like
Eg.Taenia,echinococcus,diphyllobothrium

5. NEMATELMINTHS(ROUND)
ROUND WORMS
ASCARIS.L
HOOK WORMS
NECATOR A
WHIP WORMS
TRICHURIS T
THREAD WORMS
STRONGYLOIDES.S
PIN WORMS
ENTEROBIUS V
FILARIASIS WORMS
BANCROFTI
ONCHOCERCIASIS
O.VOLVULUS
GUINEA WORMS
DRACANCULUS M
PLATYHELMINTHS
A) TREMATODES-FLUKES
BLOOD FLUKES
SCISTOSOMIASIS
LIVER FLUKES
CLONORCHIASIS
INTESTINAL FLUKES
FASCIOLOPSIASIS
LUNG FLUKES
PARAGONIMIASIS
B) CESTODES
BEEF TW
T.SAGINAT
PORK TW
T.SOLIUM
FISH TW
DIPHYLLOBO THRIUM
DWARF TW
HYMENOLEPIS.NANA

6. TYPES (CLINICAL) 1. Worms live in hosts alimentary canal.
2. Worms or larvae live in other tissues of host body like muscles , viscera , menninges , lungs, subcutaneous tissues.
INTESTINAL
A) ROUND WORMS (NEMATODES)
Ascaris lmubricods (common round worm)
Enterobius vermicularis (pin worm)
Trichuris trichuria ( whip worm)
Strongyloids stercoralis (thread worm)
Ankylostoma dudenale (hook worm)
B) TAPE WORMS (CESTODES)
Taenia saginata(Beaf) ,
Taenia solium(Pork),
Hymenolepis nana(Dwarf) ,
Diphylobothrium latum(Fish)

7. Wuchereria bancrofti 2. TISSUE WORMS
TREMATODES (Schisotomes) OR FLUKES(leaf like)
Schistosoma haematobium
Schistosoma Japonicum
Schistosoma mansoni
(These cause SCHISTASOMIASIS ) also called (BILHARZIA) means disease of blood vessels.
Clonorchis sinensis (liver fluke)
Paragonimus westermani (lung fluke)
B) TISSUE ROUND WORMS
Trichnella spiralis.
Dracunulus medinensis (guinea worm) larva
FILARIAE includes
Wuchereria bancrofti
Loa loa
Onchocerera volvulus
Brugia malayi
C) HYDATID TAPE WORM

8. NEMATHELMINTHS PLATYHELMINTHS
Long, round bodies, unsegmented worms, tapered at both ends.
Most found primarily in intestine.
Attached to the mucosa and feed host blood and tissue fluid.
Symptoms:-
Abdomianl pain
Diarrhoea
Pruritis
In severe condition cause anaemia
PLATYHELMINTHS
A)Trematodes (Flukes)
Non segmented
Acquired - ingestion of food
Mature in intestinal track
Migrate and mature in liver- Liver flukes
Lung – Lung flukes
Causes:
Diarrhoea
Abdominal pain
Anorexia
Liver flukes:
Bile duct obstruction
Liver enlargement
Cirrhosis of liver
Lung flukes:
Cough
Haemoptysis
Chest pain

9. CESTODES: Ribbon shaped Intestinal parasites
Blood flukes:
Skin
Lung
Liver
Mature
Blood
Haematuria
Frequent & painful micturation
Abdominal pain
CESTODES:
Ribbon shaped
Intestinal parasites
Head, neck followed by segments
Head hold- intestinal walls
No digestive system - host nutrients

10. ROUND WORM
Hookworm
filariasis
Pin worm male, female

11. LIFE CYCLE OF HELMINTHS

12. Adult worms live in the lumen of the small intestine. 
A female may produce approximately 200,000 eggs per day, which are passed with the feces . 
Fertile eggs embryonate and become infective , depending on the environmental conditions (optimum: moist, warm, shaded soil). 
After infective eggs are swallowed
The larvae hatch
Invade the intestinal mucosa portal, systemic circulation lungs  penetrate the alveolar walls ascend the bronchial tree to the throat, and are swallowed .  
Upon reaching the small intestine, they develop into adult worms.  
Between 2 and 3 months are required from ingestion of the infective eggs to oviposition by the adult female. 
Adult worms can live 1 to 2 years.

13. ANTHELMINTICS OR ANTIHELMINTHICS
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).
CLASSIFICATION
AGAINST NEMATODES
ALBENDAZOLE, MEBENDAZOLE, PYRANTEL PAMOATE, LEVIMASOLE, PIPERAZINE, IVERMECTIN, DIETHYLCARBAMAZINE, THIABENDAZOLE, DOXYCYCLINE
AGAINST TREMATODES
METRIFONATE, OXAMNIQUINE, BITHIONOL, TRICLABENDAZOLE
AGAINST CESTODES
NICLOSAMIDE
AGAINST TREMATODES AND CESTODES
PRAZIQUANTEL

14. MEBENDAZOLE A synthetic benzimidazole Introduced in 1972
Broad-spectrum
SPECTRUM:
100% cure rate
For round worm, hook worm, enterobius (less for Strongyloides) and trichuris (not for tissue Trichinella spiralis)
75% effective
For tape worms but not for H. nana
Hadatid cyst: prolonged treatment
Hatching of nematode eggs and larva inhibited and Ascaris eggs are killed
MECHANISM OF ACTION
Action is slow: takes 2-3 days to develop.
Inhibits microtubule synthesis
That irreversibly impairs glucose uptake
Inhibition of glucose uptake
Disruption of metabolic pathway
Resulting in the gradual immobilization and die slowly.

15. Pinworm Trichuriasis Hookworm Ascaris infections. Whipworm Enterobius
CLINICAL USES
Pinworm
Trichuriasis
Hookworm
Ascaris infections.
Whipworm
Enterobius
Trichinella spiralis
Hydatid disease
ADVERSE EFFECT
In heavy infestation cases:-
Diarrhoea
Nausea
Abdominal pain
In high dose:-
Granulocytopenia
Allergic reaction
Alopecia

16. ALBENDAZOLE PHARMACOKINETICS SPECTRUM OF ACTION
Congener of Mebendazole
Broad-spectrum activity
Excellent tolerability
Single dose administration
SPECTRUM OF ACTION
Comparable efficacy with mebendazole
Same for round worm, hook worm and enterobius
Less effective against trichuris
More effective against strongyloides
Trichinella effectiveness is almost same
More effective in tape worm (including H. nana) and hydatid larvae and ova of ascaris and hook worm
Weak microfilarial action and cutaneous larva migrans
MECHANISM OF ACTION
Binds with β-tubulin and inhibits microtubules polymerization.
Blocks glucose and other nutrients uptake.
Intestinal parasites are immobilized and die slowly.
PHARMACOKINETICS
Benzimidazole carbamate
Moderate and inconsistent oral absorption
Fatty meals enhance absorption
For intesinal worm given in empty stomach and for tissue action – with fatty meals

17. USES ADVERSE EFFECT Well tolerated GI side effects Dizziness
Prolonged used in hydatid and cysticercosis
- Headache, fever, alopecia, neutropenia, jaundice.
USES
Used on empty stomach when used against intestinal worms
With a fatty meal when used against cysticercosis, hydatid and cutaneous larva migrans .
Ascaris, hookworm, Enterobius and Trichuris
Tapeworms and strongyloidosis
Trichinosis
Neurocysticercosis
Cutaneous larva migrans
Hydatid disease
Filariasis

18. THIABENDAZOLE
First benzimidazole polyanthelmintic
Introduced in 1961
SPECTRUM
All species of nematodes infesting the g.i.t.-roundworm, hookworm, Enterobius, Trichuris, Strongyloides and Trichinella spiralis.
Inhibits the eggs of worms and kills larvae.
Symptomatic relief in cutaneous larva migrans, Trichinella spiralis larvae, guinea worm disease.
MECHANISM OF ACTION
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.

19. PHARMACOKINETICS
It is chelating agent and form stable complexes with metals including iron, but does not bind with calcium.
It can also get absorbed through skin
ADVERSE EFFECTS
Frequent
Often interfere with normal activity.
Nausea, vomiting, loss of appetite, headache, giddiness are most common.
It can impair alertness-driving and operation of machinery should be prohibited.
Itching, abdominal pain, diarrhoea.
CLINICAL USES
Because of frequent side effects and poor patient acceptability used only when other better tolerated drugs are ineffective.
strongyloidosis
Cutaneous larva migrans
Trichinosis-intestinal infestation and larvae in muscles

20. PYRANTEL PAMOATE A broad specturm SPECTRUM:
MECHANISM OF ACTION
Acts as a depolarizing neuromuscular blocker
Causes the release of acetylcholine and inhibits cholinesterase
Activation of nicotinic cholinergic receptors in the worms
Resulting in persistent depolarization
Slowly developing contracture and spastic paralysis.
Paralyzing the helminthes
Result of causing the worm to "lose its grip" on the intestinal wall and be passed out of the system by natural process.
Worms are then expelled.
A broad specturm
SPECTRUM:
Threadworm, roundworm, hookworm, Ascaris, Enterobius and Ancylostoma, Necator infestation.
Less active against
Strongyloides
Inactive against
Trichuris and other worms.

21. Very effective against luminal organisms.
ADVERSE EFFECTS
Infrequent mild transient GI disturbance
Drowsiness,headache, insomnia.
Rash ,fever
CONTRAINDICATIONS
Should not be used in liver diseases.
Pregnancy
Child under 2 years of age
CLINICAL USE
Very effective against luminal organisms.
Entrobius vermicularis (pin worm)
Ascariasis lumbricoids (common round worm)
Ancylostoma dudenale (hook worm)

22. PIPERAZINE Causes hyperpolarization of Ascaris muscle
Introduced in 1950
Highly active drug against Ascaris and Enterobius
MECHANISM OF ACTION
Causes hyperpolarization of Ascaris muscle
By a GABA agonistic action
Opening Cl- channels
That causes relaxation and depresses responsiveness to contractile action of ACh.
Flaccid paralysis
Worms are expelled alive
It does not affect neuromuscular transmission in man
CLINICAL USES
Only recommended for the treatment of ascariasis cure rate 90%.
ADVERSE EFFECTS
Safe and well tolerated.
Nausea, vomiting, abdominal discomfort and urticaria
Dizziness and excitement occur at high doses
Toxic doses produce convulsions; death is due to respiratory failure.
CONTRAINDICATIONS
In epileptics
Impaired liver or kidney functions
Pregnancy
Malnutrition

23. LEVAMISOLE, TETRAMISOLE
Tetramisole :- in the late 1960s.
Recemic; levo isomer (levamisole):- more active and is preferred.
SPECTRUM
Both are active against many nematodes
But use is restricted to ascariasis and ancylostomiasis.
Strongyloides larvae are killed, but adult worms are not sensitive.
MECHANISM OF ACTION
Two mechanisms:
The ganglia in worms are stimulated causing tonic paralysis and expulsion of live worms.
Interference with carbohydrate metabolism (inhibition of fumarate reductase) may also be contributing.

24. For Ascaris infestation
PHAMACOKINETICS
Given orally
Rapidly absorbed
Widely distributed.
Crosses the blood-brain barrier.
ADVERSE EFFECTS
Nausea,
Abdominal pain,
Giddiness,
Fatigue,
Drowsiness
Insomnia
USES
For Ascaris infestation
Levamisole is a second line drug for A. duodenale
It is less efficacious against Necator.

25. DIETHYL CARBAMAZINE CITRATE (DEC)
Developed in 1948
It is the first drug for filariasis.
Piperazine derivative
SPECTRUM
Highly selective effect on Microfilariae (Mf).
Active against Mf of W. bancrofti and B. malayi, Loa loa, onchocerca volvulus .
MECHANISM OF ACTION
Immobilizes microfilariae
Alters their surface structure
Displacing them from tissues
Making them susceptible to destruction by host defense mechanism.
ADVERSE EFFECTS
Nausea, loss of appetite, headache, weakness and dizziness
A febrile reaction with rash, pruritus, enlargement of lymph nodes and fall in BP
Leukocytosis and mild albuminuria
USES
Filariasis
Tropical eosinophilia
For Loa loa and 0. volvulus infections

26. IVERMECTIN MECHANISM OF ACTION A macrocyclic lactone
Extremely potent semisynthetic derivative
Obtained from streptomyces avermitilis
SPECTRUM
Choice for single dose treatment of
Onchocerciasis and strongyloidosis.
Highly effective in
Bancroftian, brugian filaria,cutaneous larva migrans and ascariasis,
Moderate Efficacy against
Enterobius and Trichuris
Certain insects, notably scabies and head lice are killed by ivermectin.
MECHANISM OF ACTION
Acts on the parasites by binding to a novel allosteric site on the acetylcholine nicotinic receptor to cause an increase in transmission
By opening glutamate-gated chloride channels
Chloride influx increased
Hyper polarization occurs
Resulting in paralysis of the worm.

27. MECHANISM OF ACTION Ivermectin Targets GABA receptors of parasite
Chloride ion influx enhanced
Hyper polarization occurs
Paralysis of the worm

28. Giddiness Constipation Lethargy Transient ECG changes ADVERSE EFFECT
Fatigue, dizziness, GI disturbance
Nausea
Abdominal pain
Pruritis
Giddiness
Constipation
Lethargy
Transient ECG changes
CONTRAINDICATION
Other drugs that enhance GABA
e.g Barbiturates, bnezodiazepines, valproaic acid.
Pregnancy
Imparied blood brain barrier
Children under 5 years of age.
USES
Filariasis
Strongyloidosis
Other intestinal nematodes
Scabies
Pediculosis

29. NICLOSAMIDE Inhibition of oxidative phosphorylation in mitochondria
Highly effective
Useful drug for treatment of tape worm (cestodes) infestation
Safe during pregnancy.
SPECTRUM
Against cestodes infesting man – Taenia saginata, T. solium, Diphyllobothrium latum and Hymenolepis nana, as well as threadworm.
MECHANISM OF ACTION
Inhibition of oxidative phosphorylation in mitochondria
Interference of anaerobic generation of ATP by tapeworm.
Injured worms are digested or expelled (purgation)

30. Minor abdominal symptoms Malaise Pruritis Diarrhea Light headedness
ADVERSE EFFECT
Well tolerated
No systemic toxicity
Minor abdominal symptoms
Malaise
Pruritis
Diarrhea
Light headedness
Safe during pregnancy and in patients with poor health.
CLINICAL USES
T.Saginata (Beef tape worm)
T.solium (pork tape worm),
Diphyllobothrium latum (fish tape worm)
Hymenolepis nana: It is effective against adult parasite

31. PRAZIQUANTEL MECHANISM OF ACTION PHARMACOKINETICS
Novel anthelmintic
Wide ranging activity against Schistosomes, other trematodes, cestodes and their larval forms but not nematodes.
Effective against wide variety of cestodes and tremetodes.
SCHISTOSOMIASIS
- LIVER FLUKES
- LUNG FLUKES.
Taeniasis
Neuro Cysticercosis
MECHANISM OF ACTION
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.
PHARMACOKINETICS
Absorption is enhanced with food.
Crosses blood-brain barrier

32. ADVERSE EFFECT Bitter in taste Nausea Abdominal pain Headache
Dizziness and sedation
Rashes, fever, itching and body pain
CLINICAL USES
Tapeworms
T. saginata, T. solium
H. nana, O. latum
Neurocysticercosis
Schistosomes
Other flukes

33. THANK YOU -PHARMA STREET