Transcript Beef tapeworm

Medical University of Sofia, Faculty of Medicine
Department of Pharmacology and Toxicology
Anthelmintic drugs
Insecticides
(Abstract)
Assoc. Prof. Ivan Lambev
e-mail: [email protected]
Relative
incidence
of helminth
infections
worldwide
Cestodes (tapeworms)
Beef tapeworm – Taenia saginata
Pork tapeworm – Taenia solium
Cysticercosis – Taenia solium
Fish tapeworm – Diphyllobothrium latum
Hydatid disease – Echinococcus granulosus
Worms (helminths)
Drug of choice
Tapeworms (cestodes)
Niclosamide or Praziquantel or
Albendazole
Roundworms (nematodes)
Enterobius vermicularis (pinworm)
Ascaris lumbricoides
Trichuris trichiura (whipworm)
Trichinella spiralis (trichinellosis)
Strongyloides stercoralis
Necator americanus (hookworm)
Ancylostoma duodenale
Onchocerca volvulus (Onchocercosis)
Wuchereria bancrofti (Elephantiasis)
Mebendazole or Pyrantel
Mebendazole or Pyrantel
Mebendazole or Albendazole
Mebendazole
and Thiabendazole
Thiabendazole
Mebendazole or Pyrantel
Mebendazole, Pyrantel or
Albendazole
Ivermectin
Diethylcarbamazine
Flukes (trematodes)
Schistzoma (Schistozomes)
Praziquantel
Life cycle of Taenia saginata (beef tapeworm).
Life cycle of Trichinella spiralis (cosmopolitan)
Trichinella larva encysted in a characteristic
hyalinized capsule in striated muscle tissue
Elephantiasis (Lymphatic filariasis)
of the lower extremity associated
with Wuchereria bancrofti infection
Global distribution of Schistosoma mansoni and S. intercalatum
Niclosamide blocks glucose uptake by intestinal
tapeworms. It may cause some mild gastrointestinal
symptoms.
Piperazine may cause hypersensitivity reactions,
neurological symptoms (including “worm wobble”)
and may precipitate epilepsy.
Praziquantel paralyses both adult worms and
larvae. It is extensively metabolised. Praziquantel
may cause nausea, headache, dizziness and
drowsiness; it cures with a single dose (or divided
doses in one day).
Mebendazole blocks glucose uptake by
nematodes. Mild GI distarbunces may be
caused, and it should not be used in pregnancy or in children under the age of 2.
Albendazole is similar to mebendazole.
Levamisole paralyses the musculature of
sensitive nematodes which, unable to maintain
their anchorage, are expelled by normal
peristalsis. It is may cause abdominal pain,
nausea, vomiting, headache and dizziness.
Thiabendazole inhibits cellular enzymes of
susceptible helminths. Gastrointestinal, neurological and hypersensitivity reactions, liver damage
and crystalluria may be induced.
Pyrantel depolarises neuromuscular junctions
of susceptible nematodes which are expelled in the
faeces. It cures with a single dose. It may induce
GI disturbance, headache, dizziness, drowsiness
and insomnia.
Diethylcarbamazine kills both microfilariae and
adult worms. Fever, headache, anorexia, malaise,
urticaria, vomiting and asthmatic attacks following
the first dose are due to products of destruction of
the parasite, and reactions are minimised by slow
increase in dosage over the first 3 days.
Ivermectin may cause immediate reactions due
to the death of the microfilaria. It can be effective in
a single dose, but is best repeated at 6–12-month
intervals.
Insecticides
Whereas fleas can be effectively dealt
with by disinfection of clothes, lice and
mites require the topical application of
insecticides to the infected subject.
Chlorphenothane (DDT) kills insects
after absorption of a very small amount,
e.g., via foot contact with sprayed
surfaces (contact insecticide).
The cause of death is nervous system
damage and seizures. In humans DDT
causes acute neurotoxicity only after
absorption of very large amounts.
DDT is chemically stable and degraded in
the environment and body at extremely
slow rates. As a highly lipophilic substance, it accumulates in fat tissues.
Widespread use of DDT in pest control
has led to its accumulation in food
chains to alarming levels. For this reason its use has now been banned in
many countries.
Lindane is the active gama-isomer of
hexachlorocyclohexane. It also exerts a
neurotoxic action on insects (as well as
humans). Irritation of skin or mucous
membranes may occur after topical use.
Lindane is active also against intradermal mites (Sarcoptes scabiei, causative
agent of scabies), besides lice and fleas.
It is more readily degraded than DDT.
Permethrin, a synthetic pyrethroid,
exhibits similar anti-ectoparasitic
activity and may be the drug of choice
due to its slower cutaneous absorption,
fast hydrolytic inactivation, and rapid
renal elimination