Transcript antiparasitics students

Antiparasitics
Antiparasitics…
• Make up the largest category of products available
to veterinary professionals and the general public.
• Can be OTC or Rx.
• Help to protect animals from diseases, as well as
people.
• Is an important topic of client education for
veterinary technicians (let them look under the
microscope, show them a heart filled with worms).
• Is a quickly changing market.
The ideal paraciticide is….
• Selectively toxic to the parasite and not the host.
• Does not induce resistance in the target parasite.
• Is economical.
• Effective against all parasite stages with one application.
• Fragrant or odorless.
• Environmentally safe.
General rules of antiparasitics
• Use with caution in old, young, debilitated, or
pregnant animals.
• Certain antiparasitics are risky for certain
groups of animals.
• They are only effective if most of the drug
reaches the location of the parasite.
• The client and veterinary team must
understand which part of the parasite’s life
cycle is affected by the drug and how/ when
the drug should be applied.
• Endoparasites cause infections and live inside the body.
• Ectoparasites cause infestations and live outside the body.
• Parasites in an abnormal location in a hosts’ body are aberrant.
• Anthelmintics: kill helminth worms (parasitic worms)
– Antinematodals: treat round worms
– Anticestodals: treat tapeworms
– Antitrematodals: treat flukes
• Antiprotozoals: treat single-celled organisms: Coccidia,
Giardia, Toxoplasma
• Drench vs. Pour-on
Terms
• BENZIMIDAZOLES
– In addition to nematodes, some products can
treat some flukes, cestodes, and protozoa
– Ysed in large animals, small animals, and exotics
– Usually have to apply more than one dose
consecutively
– “bendazole” suffix
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Thiabendazole (EQUIZOLE, TBZ, OMNIZOLE)
Fenbendazole (PANACUR/SAFEGUARD)
Oxibendazole (ANTHELCIDE EQ)
Albendazole (VALBAZEN)
Mebendazole (TELMIN)
ANTINEMATODALS
• ORGANOPHOSPHATES and CARBAMATES
• Inactivate acetocholinesterase in parasites. This allows
acetylcholine to overstimulate the nervous system and
eventually cause paralysis (label usually says “contains a
cholinesterase inhibitor”).
• Not used as often with animals as they used to be.
• Also used as pesticides.
• Examples: Coumaphos (BAYMIX), Dichlorvos (TASK)
ANTINEMATODALS
• ORGANOPHOSPHATES and CARBAMATES
• To remember signs of toxicity, think SLUDDE: (salivation,
lacrimation, urination, defecation, dyspnea, emesis).
Also bradycardia, miosis, muscle tremors, ataxia,
paralysis
• Treat with ATROPINE or GLYCOPYRROLATE (block
receptors for acetylcholine) and remove the
insecticide. Glycopyrrolate reverses the neurological
signs bc it crosses the blood brain barrier better than
Atropine does.
ANTINEMATODALS
ANTINEMATODALS
• Pyrantel pamoate
• Tetrahydropyrimidine
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NEMEX, STRONGID
Considered to be very safe
Often found in feed stores
Ineffective against whipworms
• Febantel and Levamisole
• Imidathiazoles
• Effective against whipworms
ANTINEMATODALS
• MACROLIDES: Avermectins and Milbemycin
• Structurally similar with a macrocyclic ring that are derived for a
Streptomyces bacterium.
• Cause paralysis and death of nematodes.
• Among the safest compounds to use (these receptors are located
behind the blood-brain barrier within the CNS in mammals)
ANTINEMATODALS
• AVERMECTINS
• Suffix -ectin
• Ivermectin, Selamectin, Doramectin, Eprinomectin, Moxidectin
• Ivermectin (many species)
• HEARTGARD, EQVALAN, IVOMEC
• Heartworm prevention, intestinal parasites, demodex, ear mites
• Oral or injectable
• Ivermectin toxicosis in collies
• Genetic (recessive) trait that causes a deficiency of P-glycoprotein, a
protein that moves drugs from the blood brain barrier cells back into
the blood
• Toxicity causes neurological signs
• Heartgard doses are safe
• No antidote
• Selamectin (small animals)
• REVOLUTION
• Heartworm preventation, internal parasites, flea
control, ear mites, sarcoptic mange (dogs), ticks
(dogs)
• Topical
• Doramectin (large animals)
• DECTOMAX
• Internal worms, grubs, lice, mange
• Injectable and pour-on
ANTINEMATODALS
ANTINEMATODALS
• Eprinomectin (large animals)
• EPRINEX
• Internal worms, grubs, lice, mange
• Pour-on
• Moxidectin (many species)
• QUEST, CYDECTIN, PROHEART 6
• Nematodes, mites, grubs, bots, lice, flies
• Paste, Pour-on, Injectable
ANTINEMATODALS
• MILBEMYCIN
– Milbemycin oxime (small animals)
• INTERCEPTOR, SENTINEL
• Heartworm preventative, hookworms, roundworms,
ear mites, mange
• Oral tablet for dogs and cats
ANTINEMATODALS
• Piperazine
• Only effective against roundworms
• Partially or fully paralyzes the worm but does
not kill it.
• Worms are sometimes passed a mass
wiggling in the stool
• Used in many species
• Often used in OTC dewormers
ANTICESTODALS
• Cause loss of intracellular calcium in the parasite,
which leads to paralysis. Also, the tapeworm’s
outer layer becomes permeable allowing antigens
to leak out and the host to produce antibodies.
• Epsiprantel
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CESTEX
Oral tablet for dogs and cats
Does not treat Echinococcus
Causes worm to disintegrate. Proglottids will not be
seen in feces after administration. Not ovicidal.
ANTICESTODALS
• Praziquantel
•Tablets for dogs and cats
•DRONCIT
•Treats Dipylidium, Taenia, and Echinococcus
•Causes worm to disintegrate. Proglottids will not be seen in
feces after administration. Not ovicidal.
•Remember that flea prevention must be administered when
treating Dipylidium.
•DRONTAL- praziquantel, pyrantel pamoate
•DRONTAL PLUS – praziquantel, pyrantel pamoate, febantel
ANTITREMATODALS
• Clorsulon is used in cattle for liver flukes
• CURATREM
• Albendazole is used in cattle for liver flukes
• VALBAZEN
• Praziquantel is used for lung flukes in small animals
• DRONCIT
ANTIPROTOZOALS
• Treat Coccidia, Giardia, and Sarcocystis
neurona (EPM)
• Amprolium
• Causes thiamin deficiency in parasite
• Treats coccidia
• CORID
• Sulfadimethoxine
• An antimicrobial that also treats coccidia
• ALBON
ANTIPROTOZOALS
• Metronidazole
• Antibacterial and anti-diarrheal that treats Giardia
• High doses may cause neurological signs
• FLAGYL
• Fenbendazole
• Benzimidazole that treats Giardia
• PANACUR
• Ponazuril
• Treats Sarcocystis neurona and coccidia in horses
• MARQUIS
ADULTICIDE
• Melarsomine Dihydrochloride
• Kills adult Dirofilaria immitis
• Arsenic intramuscular lumbar injectable drug for dogs
• IMMITICIDE
• Injection site is commonly painful; many veterinarians
provide pain-relieving medications
• Nodules may develop at injection sites
ADULTICIDE
• Melarsomine Dihydrochloride
• Exercise restriction is imperative (dying worms live in
pulmonary arteries)
• Worms will degenerate and cause inflammation in the
lungs (steroids are often given for this)
• Adulticide is not administered to cats
• Please reference provided chart for all
current medications on treating endo
and ectoparasites in small animals.
• This chart is based off of the current
CAPC recommendations.
• Please reference CAPC regularly to
stay current on these medications as
they change frequently.
IGRs
• IGR: insect growth regulator. Affect immature
stages of insects, preventing them from maturing.
No adulticidal activity.
• IDI: insect development inhibitor (a type of IGR) also
called a chitin synthesis inhibitor
• JHM: juvenile hormone mimic (a type of IGR)
• Products are distributed over an animal's skin and
work by direct contact with the flea. Adult females
absorb the drug and incorporate the IGR into the flea
eggs. These products should be used with an
adulticide.
IGRs, IDIs, JMHs
• Lufenuron is an IDI that is ingested into flea when
it feeds on an animal. Affects the flea’s ability to
produce chitin which is located within the egg and
the larvae’s exoskeleton.
• Pyriproxyfen is a JHM, which mimics juvenile
hormone that is produced by the insect’s brain.
When the insect’s body detects high levels of JH or
a JHM, it fails to fully mature to the stage of egg
production.
DRUGS THAT TREAT ECTOPARASITES
• Pyrethrins
• Extract of chrysanthemums used in many
insecticides.
• Most end in “thrin” (ex: PERMETHRIN).
• Highly toxic to cats, causes seizures and
hypersalivation. Permethrin is used in a
lot of products to repel ticks and people
mistakenly apply it to cats. Rinse product
off!
• Fish are also hypersensitive to toxicity,
use with care around water.
DRUGS THAT TREAT ECTOPARASITES
• Formamidines
• Amitraz is the most commonly used
• MITABAN for demodex treatment in dogs
(also kills ticks)
• Wear gloves when applying dip! May cause
transient sedation for up to 72 hours, hypothermia
(drip dry), and pruritus
• Use caution with collars (PREVENTIC). If lost,
monitor for signs of ingestion.
• TAKTIC for treatment of lice, mange, and
ticks on large animals
• Effects an be reversed with yohimbine,
tolazoline, and atipamezole
INSECT REPELLENTS
• Repel gnats, mosquitoes, and flies. When pyrethrins/pyrethroids
are added, fleas and ticks are repelled.
• Sprays, tags, and topicals applied to ear tips
• Used on horses and cattle to prevent flies from laying eggs on the
skin (leading to bots and warbles)
• Used on dogs with upright ears to prevent fly strike.
• Butoxypolypropylene glycol (BUTOX PPG)
• Diethyltoluamide (DEET) is often used in human products for
insect repelling. Caused death in small animals.